Contact Lens Safety: How to Wear Contact Lenses Safely and Protect Your Vision

Author: Dr Val Phua
Estimated reading time: 25 minutes

Contact lenses can provide clear vision, freedom from spectacles and greater convenience during sport and daily activities.

They can be used to correct:

• Myopia
• Hyperopia
• Astigmatism
• Presbyopia
• Unequal prescriptions between the eyes
• Selected corneal conditions

Specialised contact lenses may also be used for:

• Childhood myopia control
• Orthokeratology
• Keratoconus
• Corneal irregularity
• Aphakia
• Therapeutic protection of the cornea

However, a contact lens rests directly on the surface of the eye.

Contact lenses are medical devices rather than ordinary cosmetic accessories. Improper fitting, wear, cleaning or storage can cause complications ranging from mild irritation to a sight-threatening corneal infection.

The most important preventable risks are associated with:

• Sleeping in lenses
• Allowing lenses to contact tap water
• Swimming or showering in lenses
• Poor hand hygiene
• Reusing daily disposable lenses
• Wearing lenses beyond their replacement date
• Topping up old solution
• Inadequate lens-case cleaning
• Using saline instead of disinfecting solution
• Buying unprescribed decorative lenses
• Continuing to wear lenses despite pain, redness or reduced vision

In a Singapore case-control study, not washing the hands before handling lenses was associated with markedly greater odds of contact-lens-related microbial keratitis. Even occasional overnight wear was associated with approximately four times the risk compared with ordinary daily wear.

The central safety rule is simple:

A painful, red or light-sensitive eye in a contact-lens wearer should be treated as a possible corneal infection until proven otherwise. Remove the lens immediately and seek prompt eye assessment.

Do not wait several days to see whether the symptoms settle.

Do not continue wearing the lens because the eye “only feels slightly uncomfortable”.

Do not begin leftover steroid drops without medical advice.

A contact-lens-related corneal infection can progress quickly and may cause:

• Corneal ulceration
• Scarring
• Irregular astigmatism
• Permanent reduction of vision
• The need for corneal surgery

Most contact-lens complications are preventable.

Safe wear depends less on purchasing the most expensive lens and more on consistently following correct habits.

The Quick Answer

What Are the Most Important Contact Lens Safety Rules?

Every contact-lens wearer should:

• Wash and dry the hands before touching the lenses.
• Keep lenses and lens cases completely away from tap water.
• Remove lenses before showering, swimming or entering a hot tub.
• Avoid sleeping or napping in lenses unless specifically prescribed.
• Follow the recommended daily wearing time.
• Replace lenses exactly on schedule.
• Never reuse a daily disposable lens.
• Rub and rinse reusable lenses with the prescribed disinfecting solution.
• Use fresh solution every time.
• Never top up old solution.
• Replace the lens case regularly.
• Attend regular contact-lens examinations.
• Carry backup spectacles.
• Stop lens wear immediately for pain, redness, light sensitivity or reduced vision.

These recommendations are consistent with current CDC and FDA guidance for safe contact-lens wear and care.

Can I Sleep in Contact Lenses?

Sleeping or napping in lenses substantially increases the risk of microbial keratitis.

This risk applies even when a lens has been approved for extended or overnight wear.

A major prospective case-control study found that overnight wear increased the risk of microbial keratitis by more than five times. A Singapore study also identified occasional overnight wear as an important modifiable risk factor.

Unless overnight use is an intentional and professionally supervised part of treatment—such as orthokeratology—the safest approach is to remove lenses before sleeping.

Can I Shower in Contact Lenses?

No.

Tap water is not sterile.

Water may contain bacteria, fungi and free-living organisms such as Acanthamoeba.

Water can also cause a soft lens to swell, change shape or adhere more tightly to the cornea, increasing the possibility of surface injury and trapping organisms against the eye.

Remove lenses before:

• Showering
• Bathing
• Swimming
• Using a hot tub
• Water sports

Can I Swim in Contact Lenses?

The safest answer is no.

Use prescription swimming goggles when distance correction is required.

When lenses are unintentionally exposed to water:

• Remove them as soon as safely possible.
• Discard daily disposable lenses.
• Clean and disinfect reusable lenses for the full recommended cycle before reuse.
• Seek assessment if pain, redness, light sensitivity or blur develops.

CDC guidance advises removing lenses before water activities and discarding or properly disinfecting lenses after accidental exposure.

Are Daily Disposable Lenses the Safest?

Daily disposable lenses remove the need for:

• Cleaning
• Storage
• A lens case
• Reusing disinfecting solution

This can reduce several important sources of contamination.

However, daily disposables do not eliminate the risk of microbial keratitis.

Sleeping in them, reusing them, handling them with unwashed hands or exposing them to water can still cause infection. Studies suggest that daily disposables may reduce the severity of bacterial keratitis compared with reusable lenses, although the overall occurrence of infection is not necessarily eliminated.

Can Children Wear Contact Lenses Safely?

Many children can wear contact lenses safely when:

• They are properly fitted.
• They can follow instructions.
• Parents supervise hygiene.
• The lenses are replaced correctly.
• Regular reviews are attended.
• Water and overnight wear are avoided.

A Singapore study found that most children aged eight to eleven successfully used daily disposable lenses over three months, although corneal staining and handling difficulties occurred in some participants.

A larger paediatric safety study covering 2,713 patient-years found two presumed or probable cases of microbial keratitis, both in teenagers. Overall adverse-event rates were comparable with established adult soft-lens rates.

Age alone does not determine readiness.

Responsibility, hygiene and supervision matter more.

Why Contact Lenses Require Proper Care

The Cornea Has No Blood Vessels

The cornea is the transparent front surface of the eye.

It must remain clear for light to pass through.

Unlike many other tissues, the central cornea does not contain blood vessels.

It obtains oxygen mainly from:

• The atmosphere
• The tear film
• The aqueous humour inside the eye

A contact lens partly separates the cornea from the air.

Modern materials permit substantial oxygen transmission, but:

• Oxygen delivery is still altered.
• Tear exchange may be reduced.
• The lens can trap deposits and organisms.
• The lens can mechanically interact with the eyelids and cornea.

The Tear Film Protects the Eye

The tear film:

• Lubricates the ocular surface
• Supplies nutrients
• Washes away debris
• Contains antimicrobial substances
• Maintains a smooth optical surface

Contact lenses divide the tear film into:

• A pre-lens tear film
• A post-lens tear film

This can contribute to:

• Tear evaporation
• Reduced lubrication
• Dryness
• Deposit formation
• Fluctuating vision

The Corneal Epithelium Is a Protective Barrier

The corneal epithelium forms the outer protective surface.

Small epithelial defects may result from:

• A poorly fitting lens
• A damaged lens
• Excessive wearing time
• Dryness
• Lens deposits
• Rubbing the eye
• Forceful lens removal
• Water-related lens swelling

When this barrier is disrupted, microorganisms have an easier route into the cornea.

What Is Microbial Keratitis?

Microbial keratitis is an infection of the cornea.

It may be caused by:

• Bacteria
• Acanthamoeba
• Fungi
• Less commonly, other organisms

Pseudomonas aeruginosa is a particularly important cause of rapidly progressive bacterial keratitis in contact-lens wearers.

Possible symptoms include:

• Pain
• Redness
• Light sensitivity
• Tearing
• Discharge
• Reduced vision
• A white corneal spot
• Difficulty opening the eye

Microbial keratitis is uncommon relative to the total number of contact-lens wearers, but it is one of the most serious complications of lens use.

Contact Lenses and Infection Risk

Risk depends on:

• Lens-wearing schedule
• Overnight use
• Hygiene
• Water exposure
• Lens replacement
• Case replacement
• Smoking
• Lens care system
• Frequency of wear
• Individual ocular-surface health

A large case-control study found that wearing lenses beyond their intended replacement period, sleeping in lenses and poor hygiene significantly increased microbial-keratitis risk.

The Essential Contact Lens Safety Rules

Rule 1: Wash and Dry Your Hands

Wash your hands with soap and running water before:

• Inserting lenses
• Removing lenses
• Cleaning reusable lenses
• Touching the lens case
• Handling a dropped lens

Dry the hands completely using a clean, lint-free towel.

Wet fingers may transfer:

• Tap-water organisms
• Soap residue
• Skin bacteria
• Moisture that makes lenses difficult to handle

A Singapore study identified failure to wash the hands before lens handling as one of the strongest modifiable risk factors for contact-lens-related microbial keratitis.

Is Hand Sanitiser Enough?

Alcohol hand sanitiser may leave residue that stings the eye.

When possible:

1. Wash with soap and water.
2. Rinse thoroughly.
3. Dry completely.
4. Handle lenses only after the hands are dry.

When ordinary handwashing is temporarily unavailable, use spectacles rather than improvising unsafe lens handling.

Keep Fingernails Clean

Long or sharp nails may:

• Scratch the lens
• Scratch the cornea
• Trap cosmetics or debris
• Make removal more difficult

Use the fingertip rather than the nail to handle a soft lens.

Rule 2: Keep Contact Lenses Away from Water

Never use water to:

• Rinse lenses
• Store lenses
• Clean the case
• Wet a suction remover
• Replace solution
• Lubricate a lens
• Free a lens that feels dry

This includes:

• Tap water
• Bottled water
• Distilled water
• Filtered water
• Mineral water
• Lake water
• Sea water
• Swimming-pool water
• Hot-tub water

Water that is safe to drink is not sterile enough for contact-lens care.

Why Is Acanthamoeba Important?

Acanthamoeba is a microscopic free-living organism found in multiple water and soil environments.

Acanthamoeba keratitis can cause:

• Severe pain
• Prolonged inflammation
• Corneal nerve involvement
• Ring-shaped corneal infiltration
• Months of intensive treatment
• Corneal scarring
• The need for corneal transplantation
• Permanent visual loss

CDC guidance specifically warns that Acanthamoeba may be present in tap, lake, well and other water sources.

What if Water Accidentally Enters My Eye?

Remove the lens as soon as possible.

For a daily disposable lens:

• Discard it.
• Use a new lens only when the eye feels completely normal.

For a reusable lens:

• Rub and disinfect it using the prescribed system for the full cycle.
• Do not simply rinse it briefly.
• Do not reinsert it immediately.

Seek prompt assessment if symptoms develop.

Rule 3: Do Not Sleep or Nap in Lenses

Sleeping changes the eye environment.

During sleep:

• The eyelids are closed.
• Oxygen exposure falls.
• Tear exchange decreases.
• Lens movement is reduced.
• Organisms and inflammatory material may remain trapped.

Even a short nap can expose the eye to these conditions.

A prospective case-control study found that overnight wear increased microbial-keratitis risk by approximately 5.4 times.

What About Extended-Wear Lenses?

Some lenses are approved for overnight wear.

Approval means that the lens meets specified requirements for that wearing schedule.

It does not mean that sleeping in the lens is free of infection risk.

An eye-care professional may occasionally prescribe extended wear for a specific reason, but daily removal remains safer from an infectious-risk perspective.

What if I Accidentally Fall Asleep?

After waking:

• Do not pull out a dry or tightly adherent lens immediately.
• Blink several times.
• Apply preservative-free lubricating drops when appropriate.
• Allow the lens to move normally.
• Wash and dry your hands.
• Remove the lens gently.
• Discard it if it is daily disposable.
• Leave the lens out if the eye is irritated.

Arrange assessment if there is:

• Persistent pain
• Redness
• Light sensitivity
• Reduced vision
• A white corneal spot

Rule 4: Follow the Replacement Schedule

A daily disposable lens is designed for one day.

A two-week lens is not a monthly lens.

A monthly lens should not be worn for several months simply because it still feels comfortable.

Using lenses beyond their replacement date allows:

• Deposits to accumulate
• Surface wettability to decline
• Microorganisms to adhere
• Lens material to deteriorate
• Comfort and vision to worsen

Case-control research has identified wearing lenses beyond their intended replacement period as a major risk factor for microbial keratitis.

When Does the Replacement Period Begin?

For reusable soft lenses, the replacement period generally begins when the blister is opened—not according to the number of individual days on which the lens was worn.

For example, a monthly lens opened on 1 August should not be kept until October merely because it was used only on weekends.

Follow the instructions for the specific prescribed product.

Rule 5: Never Reuse Daily Disposable Lenses

A daily disposable lens should be:

1. Removed.
2. Discarded.
3. Replaced with a new sterile lens at the next wear.

Do not:

• Clean and store it overnight
• Reinsert it later the same day after unsafe storage
• Wear it on a second day
• Share it
• Place it in tap water or saline

Daily disposable lenses are not manufactured or prescribed for repeated cleaning and storage.

Rule 6: Use Fresh Disinfecting Solution

For reusable lenses:

• Empty the old solution completely.
• Clean the case as directed.
• Fill it with fresh disinfecting solution.
• Use the full recommended soaking time.

Never top up old solution.

“Topping off” dilutes the fresh disinfectant and leaves organisms and deposits from the previous cycle within the case.

Both CDC and FDA guidance advise against mixing fresh and used solution.

Rule 7: Rub and Rinse Reusable Lenses

Mechanical rubbing helps remove:

• Protein deposits
• Lipids
• Mucus
• Cosmetics
• Biofilm
• Microorganisms

Follow the rubbing and rinsing instructions for:

• The prescribed lens
• The prescribed solution
• The specific care system

Do not assume that every solution is interchangeable.

Rule 8: Care for the Lens Case

The lens case can become contaminated even when the lenses appear clean.

After each use:

1. Empty the old solution.
2. Rub and rinse the case using the recommended contact-lens solution.
3. Allow it to air-dry.
4. Store it upside down with the caps off in a clean area.

Do not clean the case with tap water.

CDC recommends replacing a contact-lens case at least every three months, or earlier if it is damaged or contaminated.

Keep the Case Away from the Sink and Toilet

Bathrooms are humid and exposed to:

• Water splashes
• Aerosols
• Cosmetics
• Cleaning chemicals
• Environmental microorganisms

Store the case in a clean, dry area.

Do Not Use a Damaged Case

Replace the case when it is:

• Cracked
• Warped
• Discoloured
• Slimy
• Heavily deposited
• Difficult to close
• Contaminated by water

Rule 9: Use the Correct Care System

Different lenses may require different systems.

Options include:

• Multipurpose disinfecting solution
• Hydrogen peroxide systems
• Separate cleaners for rigid lenses
• Saline for specific rinsing steps

Saline solution does not disinfect contact lenses.

It should not replace multipurpose or hydrogen peroxide disinfection.

Multipurpose Solution

Multipurpose solution may be used to:

• Rub
• Rinse
• Disinfect
• Store

depending on its instructions and compatibility with the lens.

Do not:

• Change brands repeatedly without advice
• Use expired solution
• Touch the bottle tip
• Transfer solution into another container
• Leave the bottle open
• Use it beyond the stated period after opening

Hydrogen Peroxide Systems

Hydrogen peroxide systems can provide effective disinfection and are generally preservative-free.

However, the peroxide must be completely neutralised before the lenses are placed on the eyes.

Non-neutralised peroxide can cause:

• Severe burning
• Redness
• Tearing
• Corneal epithelial injury
• Temporary visual reduction

Use only:

• The special case provided with the system
• Fresh peroxide solution
• The complete manufacturer-specified neutralisation period

Do not rinse a lens with non-neutralised peroxide immediately before insertion.

FDA guidance emphasises that peroxide must be neutralised and that the special case supplied with each new bottle should be used.

Homemade Saline

Never use homemade salt water.

Its:

• Salt concentration
• pH
• Sterility
• Chemical composition

cannot be controlled safely.

Eye Drops Are Not Contact Lens Solution

Lubricating eye drops do not necessarily:

• Clean
• Disinfect
• Store
• Remove deposits

Only products specifically approved or prescribed for the required purpose should be used.

Rule 10: Never Share Contact Lenses

Do not share:

• Clear contact lenses
• Coloured contact lenses
• Cosmetic lenses
• Ortho-K lenses
• Trial lenses intended for one person

Sharing can transfer:

• Bacteria
• Viruses
• Fungi
• Tear-film proteins
• Cosmetics
• Other contaminants

Another person’s lens may also have the wrong:

• Diameter
• Base curve
• Power
• Material
• Fit

Rule 11: Attend Regular Contact Lens Reviews

A contact-lens examination assesses more than the spectacle prescription.

It may include:

• Lens centration
• Lens movement
• Corneal staining
• Limbal redness
• Tear-film quality
• Eyelid health
• Papillary conjunctivitis
• Corneal oxygen response
• Visual acuity
• Replacement compliance
• Hygiene habits

A lens may feel comfortable while producing changes that the wearer cannot see.

CDC recommends regular eye-care review, commonly annually or at the interval advised by the clinician.

Rule 12: Carry Backup Spectacles

A current pair of glasses allows the wearer to remove the lenses safely when:

• The eyes become dry
• A lens is lost
• The lens tears
• Redness develops
• Travel disrupts the routine
• The wearer becomes unwell
• Water exposure occurs
• A long day becomes uncomfortable

Do not continue wearing an unsafe lens simply because no spectacles are available.

Different Types of Contact Lenses

Daily Disposable Soft Lenses

A fresh sterile lens is opened for each wearing day and discarded after removal.

Advantages

• No cleaning
• No storage case
• Reduced deposit accumulation
• Convenient for occasional wear
• Useful during travel
• Fewer opportunities for care-solution errors

Limitations

• Must not be reused
• Water and sleeping risks remain
• Incorrect fit can still injure the eye
• Cost may be higher for daily wear
• Packaging waste is greater

Daily disposables may reduce the severity of bacterial keratitis compared with reusable lenses, but unsafe behaviour can still lead to infection.

Reusable Soft Lenses

These include lenses replaced:

• Every two weeks
• Monthly
• At another specified interval

They require:

• Daily cleaning
• Disinfection
• Proper storage
• Lens-case care
• Exact replacement timing

Reusable lenses may be suitable and safe when care is excellent.

A recent multicentre analysis found that reusable lenses were associated with more severe bacterial keratitis than compliant daily disposable wear among patients who developed infection.

Rigid Gas-Permeable Lenses

Rigid lenses may be used for:

• Keratoconus
• Corneal irregularity
• High refractive errors
• Orthokeratology
• Selected myopia-control strategies

They require a care system compatible with the lens material.

Do not use soft-lens products on rigid lenses unless specifically approved.

Scleral Lenses

Scleral lenses rest on the white part of the eye and vault over the cornea.

They may be prescribed for:

• Keratoconus
• Corneal scars
• Severe dry eye
• Irregular corneas
• Post-surgical conditions

Insertion commonly requires filling the lens bowl with the solution prescribed by the specialist.

The wearer should not improvise using:

• Tap water
• Homemade saline
• Inappropriate preserved products

Scleral lenses require specialised fitting and follow-up.

Orthokeratology Lenses

Ortho-K lenses are rigid lenses worn during sleep to temporarily reshape the cornea and slow childhood myopia progression.

Because planned overnight use is part of the treatment, strict safety measures are essential:

• Topographic fitting
• Frequent early follow-up
• Daily disinfection
• No tap water
• Close parental supervision
• Immediate removal for symptoms

The overnight schedule does not make these lenses risk-free.

Contact Lenses and Water

Showering

Remove lenses before entering the shower.

Closing the eyes does not reliably prevent water exposure.

Water may enter when:

• Washing the face
• Shampooing
• Rinsing the hair
• Opening the eyes briefly
• Touching lenses with wet fingers afterwards

Swimming Pools

Chlorinated pool water is not sterile.

Chlorination reduces many organisms but does not make pool water safe for contact-lens storage or ocular exposure.

Use:

• Prescription goggles
• Properly fitting swimming goggles
• Spectacles before and after swimming

Sea, Lakes and Rivers

Natural bodies of water contain:

• Bacteria
• Protozoa
• Fungi
• Sediment
• Organic debris

Do not swim in contact lenses.

Hot Tubs and Spas

Warm water may support microbial growth.

The combination of:

• Warmth
• Water
• Contact lenses
• Reduced hygiene

makes hot-tub lens wear particularly unsafe.

Water Sports

For:

• Kayaking
• Sailing
• Wakeboarding
• Surfing
• Diving

use prescription goggles or another professionally advised correction method.

A lens lost under water should not be retrieved and reinserted.

Contact Lenses During Travel

Before Travelling

Pack:

• Sufficient lenses
• Current spectacles
• Extra solution
• Spare lens cases
• Prescribed eye drops
• Lens parameters or prescription
• Clinic contact information

Do not rely on finding an identical lens or care system overseas.

Carry Lenses in Hand Luggage

Checked luggage may be:

• Delayed
• Lost
• Exposed to temperature extremes

Keep essential supplies accessible.

Do Not Transfer Solution into Unlabelled Containers

Transferring solution may:

• Contaminate it
• Create confusion
• Remove expiry information
• Lead to accidental peroxide misuse

Use original travel-sized containers where possible.

On an Aircraft

Cabin air is dry.

Consider:

• Wearing spectacles on long flights
• Using compatible lubricating drops
• Avoiding sleep in lenses
• Removing lenses before an overnight flight

Do not remove or insert lenses in an aircraft bathroom unless hygienic handling is genuinely possible.

Hotel Bathrooms

Keep lenses and cases away from:

• Sink splashes
• Shower spray
• Towels of uncertain cleanliness
• Shared toiletries

Camps and Sleepovers

Children should wear lenses only when:

• Clean handwashing is available
• The care system can be followed
• A responsible adult can supervise when needed
• Backup glasses are present

Spectacles may be safer for camps with:

• Swimming
• Limited clean facilities
• Late nights
• Shared bathrooms
• Poor supervision

Contact Lenses and Sport

Contact lenses may offer:

• A wider unobstructed visual field
• Better compatibility with helmets
• Less fogging
• Greater convenience

However, contact lenses do not protect against eye injury.

Use appropriate protective eyewear for:

• Racquet sports
• Ball sports
• Combat sports
• Industrial activity
• High-speed projectiles

Make-Up and Cosmetic Products

Insert Lenses Before Applying Make-Up

This reduces the risk of transferring:

• Powder
• Mascara
• Eyeliner
• Foundation
• Cream

onto the lens during insertion.

Remove Lenses Before Removing Make-Up

This reduces contact with:

• Cleansers
• Oils
• Make-up remover
• Loose particles

Avoid Applying Products to the Inner Eyelid Margin

Cosmetics applied directly over the meibomian-gland openings may contribute to:

• Tear-film instability
• Lens deposits
• Irritation

Replace Contaminated Cosmetics

Do not continue using eye cosmetics after:

• An eye infection
• Significant conjunctivitis
• Contamination
• Expiry
• Changes in smell or texture

Do not share eye make-up.

Coloured and Decorative Contact Lenses

Decorative lenses are still contact lenses even when they have no refractive power.

They require:

• An eye examination
• Proper fitting
• A valid prescription where required
• Safe purchase
• Correct care
• Follow-up

Poorly fitted decorative lenses can cause:

• Corneal abrasion
• Infection
• Conjunctivitis
• Reduced vision
• Permanent visual damage

FDA guidance warns against purchasing decorative lenses from unregulated sellers, novelty stores, beauty shops or websites that do not require a prescription.

Why “One Size Fits All” Is Unsafe

Eyes differ in:

• Corneal curvature
• Corneal diameter
• Pupil size
• Tear film
• Eyelid anatomy

A poorly fitting lens may:

• Move excessively
• Bind tightly
• Reduce oxygen delivery
• Scratch the cornea
• Trap debris

Do Not Share Coloured Lenses

Sharing coloured lenses can transmit infection even when the lens appears clean.

Contact Lenses for Children and Teenagers

Is There a Minimum Age?

There is no universal minimum age.

Suitability depends on whether the child can:

• Follow hygiene instructions
• Avoid water
• Remove the lenses when symptoms develop
• Avoid sleeping in the lenses
• Replace them correctly
• Attend reviews

A responsible eight-year-old with strong parental supervision may be safer than an irresponsible teenager.

Daily Disposable Lenses for Children

Daily disposables are often practical because they avoid:

• Cleaning errors
• Case contamination
• Topping off
• Reuse of old solution

A Singapore paediatric study showed that most children aged eight to eleven successfully wore daily disposable lenses, although some experienced handling difficulties and corneal staining.

Parental Supervision

Parents should initially supervise:

• Handwashing
• Insertion
• Removal
• Disposal
• Recognition of redness
• Replacement ordering
• Appointment attendance

School Use

Children should have:

• Backup spectacles
• A clean storage option if lenses must be removed
• Instructions not to rinse a lens with tap water
• A plan for redness or a lost lens

A daily disposable lens that falls onto an unclean surface should generally be discarded rather than rinsed and reinserted.

Teenagers

Teenagers may be more likely to:

• Nap in lenses
• Stretch replacement schedules
• Share decorative lenses
• Wear lenses during swimming
• Skip follow-up
• Use make-up around the lenses

Clear family rules should be agreed before lens wear begins.

Contact Lenses and Myopia Control

Some soft contact lenses contain specialised optical zones designed to slow childhood myopia.

The safety principles remain the same.

The myopia-control benefit does not justify:

• Sleeping in a daytime lens
• Swimming in lenses
• Reusing daily disposables
• Wearing lenses during an infection
• Missing corneal reviews

If a child cannot use lenses safely, spectacle-based myopia control may be more appropriate.

Dry Eye and Contact Lens Discomfort

Common Symptoms

Contact-lens discomfort may cause:

• Burning
• Grittiness
• Awareness of the lens
• End-of-day dryness
• Fluctuating vision
• Redness
• Watery eyes
• Reduced wearing time

Possible Causes

• Inadequate tear production
• Rapid tear evaporation
• Meibomian-gland dysfunction
• Allergy
• Excessive wearing time
• Deposits
• Poor lens fit
• Air conditioning
• Screen use
• Incomplete blinking
• Outdated lenses

Do Not Simply Change Brands Repeatedly

A proper assessment should consider:

• Tear-film quality
• Eyelid disease
• Corneal staining
• Lens material
• Lens design
• Replacement schedule
• Care solution
• Wearing habits

Lubricating Drops

Use only drops compatible with contact-lens wear.

Some products:

• Contain preservatives
• Are too viscous
• Are intended for use only after lens removal

Follow the product and clinician instructions.

Allergy and Contact Lenses

Allergy may cause:

• Itching
• Mucus
• Redness
• Lens deposits
• Papillary conjunctivitis
• Lens displacement

Avoid rubbing the eyes.

Treatment may include:

• Temporary lens cessation
• Allergy medication
• Improved lens replacement
• Daily disposables
• Eyelid hygiene
• Reassessment of fit

Contact Lens Papillary Conjunctivitis

This inflammatory reaction affects the inner surface of the upper eyelid.

Symptoms may include:

• Itching
• Mucus
• Reduced lens tolerance
• Lens movement
• Awareness of the lens
• Blurred vision

Management may require:

• Stopping lenses temporarily
• Treating allergy
• Changing lens material or replacement frequency
• Improving deposit control

When Not to Wear Contact Lenses

Avoid lens wear when:

• The eye is red
• The eye is painful
• Vision is reduced
• There is significant discharge
• Light sensitivity is present
• The lens has torn
• The eye has been injured
• A chemical has entered the eye
• An infection is suspected
• Hygiene cannot be performed properly

Respiratory Illness

A mild cold does not automatically prevent lens wear.

However, spectacles may be preferable when the wearer:

• Feels unwell
• Is sleeping more
• Frequently touches the face
• Cannot maintain normal hygiene
• Is taking medication that worsens dryness
• Has red or watery eyes

Eye Drops and Medication

Do not place medication over contact lenses unless specifically instructed.

Some drops require the lenses to be removed because of:

• Preservatives
• Drug absorption into the lens
• Reduced treatment effectiveness
• Potential toxicity

Eye Injury

Remove the lens and seek assessment after:

• Blunt trauma
• A foreign body
• Chemical exposure
• A scratched eye
• Sudden visual loss

Do not use the lens as a bandage unless it has been medically prescribed as a therapeutic bandage lens.

Recognising a Contact Lens Emergency

Warning Symptoms

Remove the lens immediately when there is:

• Eye pain
• Increasing redness
• Light sensitivity
• Reduced vision
• Persistent tearing
• Discharge
• Marked foreign-body sensation
• Difficulty opening the eye
• A white spot on the cornea
• One eye becoming significantly worse than the other

Pain Versus Mild Dryness

Mild end-of-day awareness may improve after lens removal.

Pain that is:

• Persistent
• Increasing
• Associated with redness
• Associated with light sensitivity
• Associated with reduced vision

is not ordinary lens dryness.

A White Corneal Spot

A white spot may represent:

• An infiltrate
• A corneal ulcer
• An infection
• A scar

It requires urgent assessment.

What Should I Do?

1. Remove the lens.
2. Do not reinsert it.
3. Use spectacles.
4. Contact an eye-care professional urgently.
5. Bring the lens, case and solution when instructed.
6. Report water exposure, sleeping and hygiene honestly.

Should I Keep the Lens?

When infection is suspected, the clinician may wish to inspect or culture:

• The lens
• The lens case
• The care solution

Place them aside as directed rather than cleaning everything before the appointment.

Do Not Use Leftover Steroid Drops

Steroid eye drops may:

• Suppress inflammation
• Reduce pain temporarily
• Allow an infection to worsen
• Alter the appearance of the ulcer
• Delay diagnosis

Use them only under ophthalmic supervision.

Do Not Patch the Eye

Patching may create a warm, closed environment that worsens certain infections.

Do Not Wait for the Next Morning

A painful red contact-lens eye may deteriorate over hours.

Prompt treatment can affect:

• Scar size
• Treatment duration
• Final vision
• Need for surgery

Common Contact Lens Complications

Corneal Abrasion

A corneal abrasion is a defect in the epithelial surface.

Possible causes include:

• Fingernail injury
• Torn lens
• Dry lens removal
• Foreign material
• Poor fit

Symptoms include:

• Pain
• Tearing
• Foreign-body sensation
• Light sensitivity

A contact-lens-related abrasion requires assessment because infection may develop in the disrupted surface.

Sterile Corneal Infiltrate

An inflammatory infiltrate may occur without active microbial infection.

It may still cause:

• Redness
• Discomfort
• Light sensitivity
• A white corneal spot

Clinical examination is required because it can be difficult to distinguish from early infection.

Corneal Ulcer

A corneal ulcer involves epithelial loss with underlying inflammation or infection.

It may heal with a scar.

Central ulcers are particularly threatening to vision.

Contact Lens Acute Red Eye

This syndrome is often associated with sleeping in contact lenses.

Symptoms may include:

• Sudden redness
• Pain
• Tearing
• Light sensitivity

Lens wear should stop immediately.

Corneal Neovascularisation

Chronic low oxygen exposure or inflammation may cause new blood vessels to grow into the normally clear cornea.

Risk factors may include:

• Excessive wear
• Poorly fitting lenses
• Low oxygen transmission
• Overnight wear

Early changes may not cause symptoms.

Corneal Warpage

Long-term or irregular lens wear can alter the measured corneal shape.

This may affect:

• Refraction
• Corneal topography
• Keratoconus assessment
• LASIK or SMILE planning
• Cataract-surgery calculations

The clinician may ask the wearer to stop lenses before obtaining accurate measurements.

Giant Papillary Conjunctivitis

This may cause:

• Itching
• Mucus
• Poor lens tolerance
• Excessive lens movement

It is associated with mechanical irritation, deposits and allergy.

Acanthamoeba Keratitis

Acanthamoeba infection is particularly associated with contact-lens and water exposure.

It may initially be mistaken for:

• Herpes simplex keratitis
• Bacterial keratitis
• A simple abrasion

Early symptoms may appear more severe than the initial visible findings.

Treatment may be prolonged and difficult.

Fungal Keratitis

Fungal infection is less common in ordinary contact-lens wear than bacterial infection but may occur, particularly following:

• Trauma with plant material
• Contaminated solutions
• Environmental exposure
• Inappropriate steroid use

Daily Disposable Versus Reusable Lenses

Does Daily Disposable Automatically Mean Safe?

No.

A daily disposable wearer can still develop infection after:

• Sleeping
• Water exposure
• Poor handwashing
• Reusing a lens
• Wearing a damaged lens
• Continuing through pain

A study of daily disposable wearers found that overnight use and infrequent handwashing remained significant microbial-keratitis risk factors.

Why May Reusable Lenses Carry Greater Severe-Disease Risk?

Reusable wear introduces additional contamination points:

• Cleaning
• Rinsing
• Storage
• Case hygiene
• Solution handling
• Replacement timing

Recent case-control data suggest reusable lenses were associated with more severe bacterial keratitis than compliant daily disposable use.

Which Is Best?

The best lens is one that:

• Fits properly
• Provides clear vision
• Is suitable for the ocular surface
• Matches the wearer’s lifestyle
• Can be used consistently and safely

A reusable lens with excellent care may be safer than a daily disposable that is repeatedly slept in or reused.

Common Myths

“Contact Lenses Can Move Behind the Eye”

False.

The conjunctiva forms a continuous barrier between the eyelid and eyeball.

A lens may move beneath an eyelid, but it cannot travel behind the eye.

“Tap Water in Singapore Is Clean, So It Is Safe for Lenses”

False.

Drinking-water safety does not mean sterility for contact-lens care.

“Saline Disinfects Contact Lenses”

False.

Saline rinses but does not provide adequate disinfection.

“I Can Top Up the Solution Because It Still Looks Clear”

False.

Clear solution may contain organisms and deposits.

“A Daily Disposable Can Be Worn Again if It Looks Clean”

False.

It is intended for one day of wear.

“Sleeping for Twenty Minutes Is Harmless”

False.

A nap still creates a closed-eye environment.

“Extended-Wear Approval Means There Is No Infection Risk”

False.

Approval does not eliminate the additional risk associated with sleeping in lenses.

“Closing My Eyes in the Shower Protects the Lenses”

Not reliably.

Water can still contact the eye or contaminate the hands.

“Swimming Goggles Make Contact Lens Swimming Completely Safe”

Goggles may leak.

Prescription goggles without contact lenses are safer.

“Expensive Lenses Cannot Cause Infection”

False.

Behaviour and hygiene are major determinants of risk.

“Silicone Hydrogel Lenses Prevent All Oxygen Problems”

False.

They transmit more oxygen than many traditional materials but do not eliminate infection, mechanical complications or inflammatory problems.

“If the Lens Feels Comfortable, It Must Be Healthy”

False.

Corneal staining, neovascularisation or deposits may be present without major discomfort.

“Redness Is Normal for Contact Lens Wearers”

Persistent redness is not normal.

“Antibiotic Drops Can Be Used Whenever the Eye Is Red”

False.

The diagnosis and appropriate treatment depend on the cause.

“Steroid Drops Settle Redness, So They Are Safe”

False.

Steroids may worsen an undiagnosed infection.

“Decorative Lenses Do Not Need a Prescription Because They Have No Power”

False.

They still require proper fitting and care.

“Children Are Automatically Too Young for Contact Lenses”

False.

Suitability depends on maturity and supervision.

“Children Are Safer Because They Wear Lenses for Fewer Years”

Not necessarily.

Safe habits are required from the first day.

“If My Vision Is Clear, My Ortho-K Lenses Are Safe”

False.

Corneal health and lens hygiene require regular assessment.

Frequently Asked Questions

How Many Hours Can I Wear Contact Lenses?

The safe wearing time depends on:

• Lens material
• Lens design
• Ocular surface
• Environment
• Prescription
• Individual tolerance
• Professional advice

Do not extend wear simply because another person wears their lenses longer.

Should I Take a Contact Lens Break Every Day?

All ordinary daily-wear lenses should be removed before sleep.

Some people benefit from additional spectacle time when:

• The eyes are dry
• Wearing days are long
• Air conditioning is intense
• Screen use is prolonged
• Allergy is active

Can I Wear Contact Lenses Every Day?

Many people can, provided:

• The eyes remain healthy.
• The lenses are appropriate.
• Wear and replacement instructions are followed.
• Regular reviews are attended.

Can I Wear Lenses for Twenty-Four Hours?

Not unless this is specifically prescribed.

Ordinary daily lenses should not be used continuously through day and night.

Can I Wear a Daily Disposable Twice on the Same Day?

Once removed, the safest approach is to discard it.

A daily disposable should not be stored casually for reinsertion.

Can I Put a Lens in My Mouth?

No.

Saliva contains microorganisms and does not disinfect the lens.

Can I Use Bottled Water?

No.

Bottled water is not sterile contact-lens solution.

Can I Rinse My Eyes with Tap Water While Wearing Lenses?

No.

Remove the lenses first.

Can I Wear Lenses in the Rain?

Ordinary rain exposure is usually manageable, but avoid allowing water to enter the eyes.

Remove and replace the lenses when they become contaminated.

Can I Wear Contact Lenses at the Beach?

Wear spectacles or prescription sunglasses.

Do not swim in lenses or handle them with sandy, wet hands.

What if My Lens Falls into the Sink?

Discard it if it is daily disposable.

A reusable lens should be cleaned and disinfected for the full cycle, but a lens that has contacted a dirty or wet surface may be safer to replace.

What if My Lens Falls onto the Floor?

Discard a daily disposable.

Reusable lenses require proper cleaning, inspection and disinfection before reuse.

Do not rinse and immediately reinsert them.

What if a Lens Tears in My Eye?

Wash and dry your hands, then remove the pieces gently.

Seek assessment if:

• A fragment cannot be found
• Pain persists
• Redness develops
• Vision remains blurred

Can a Contact Lens Become Stuck?

A dry lens may adhere temporarily.

Use appropriate lubricating drops, blink and allow the lens to move before gentle removal.

Persistent inability to remove a lens requires professional help.

Should I Use Tweezers?

Do not use ordinary household tweezers.

Use only accessories specifically designed and prescribed for the lens type.

Can I Sleep in Contact Lenses During an Overnight Flight?

No.

Use spectacles.

Can I Wear Contact Lenses When I Have a Cold?

Possibly, but spectacles are safer when hygiene, comfort or alertness is reduced.

Can I Wear Lenses with Conjunctivitis?

No.

Stop wear and obtain advice.

Do not resume until the infection or inflammation has resolved and the clinician approves.

Should I Throw Away Lenses After an Eye Infection?

The affected lenses, case and opened solution may need replacement.

Follow the treating clinician’s instructions.

Can I Use Expired Contact Lenses?

No.

Do not use lenses beyond their expiry date even when the blister remains sealed.

Can I Use Expired Solution?

No.

Does Contact Lens Solution Expire After Opening?

Yes.

Follow both:

• The printed expiry date
• The discard period after opening

Can I Switch Solution Brands?

Discuss the change with the fitting professional.

Some combinations of:

• Lens material
• Preservative
• Ocular surface

are better tolerated than others.

Are Hydrogen Peroxide Systems Better?

They may be useful for:

• Deposit control
• Preservative sensitivity
• Selected reusable lenses

They must be fully neutralised and used only with the proper case.

Why Did Hydrogen Peroxide Burn My Eye?

The solution may not have been fully neutralised, or the wrong case or soaking time may have been used.

Remove the lens and irrigate according to medical advice.

Persistent pain or blur requires examination.

Can I Wear Contacts After LASIK or SMILE?

Some patients can, but fitting may be different because the corneal shape has changed.

Specialised assessment may be required.

Can I Wear Contacts After Cataract Surgery?

Yes in selected patients, after the eye has healed and the surgeon approves.

Can I Wear Contact Lenses with Dry Eye?

Possibly.

The dry-eye cause should be treated, and the lens type and wearing time adjusted appropriately.

Can I Wear Contact Lenses with Keratoconus?

Yes.

Rigid, hybrid or scleral lenses may provide better vision than spectacles, but fitting must be specialised.

Can Contact Lenses Stop Myopia?

Ordinary contact lenses correct vision but do not reliably slow axial elongation.

Selected dual-focus or multifocal contact lenses and Ortho-K lenses are designed for myopia control.

Can My Child Wear Myopia-Control Contact Lenses for Sport?

Yes, when fitted appropriately and used with safe hygiene.

Protective eyewear may still be necessary.

How Often Should Contact Lens Wearers Have Eye Examinations?

Commonly at least annually, although:

• Children
• Ortho-K wearers
• Scleral-lens wearers
• Patients with ocular-surface disease
• New wearers

may require more frequent review.

Should I Bring My Lenses to the Examination?

Yes.

Bring:

• The lenses
• Packaging
• Case
• Solution
• Backup spectacles

The clinician may need to assess the lenses on the eyes.

Can I Drive in Contact Lenses?

Yes, when:

• Vision meets the driving requirement
• The lenses are comfortable
• There is no significant blur or glare
• Backup spectacles are available

Do not drive with a painful red eye or a missing lens that causes significant visual imbalance.

When to Seek Urgent Eye Care

Seek prompt or same-day assessment for:

• Contact-lens-related pain
• Redness with light sensitivity
• Reduced vision
• A white corneal spot
• Increasing discharge
• Severe tearing
• Difficulty opening the eye
• Persistent symptoms after lens removal
• Symptoms following swimming or showering in lenses
• Symptoms after sleeping in lenses
• A chemical or peroxide injury

These symptoms may indicate:

• Microbial keratitis
• Corneal ulcer
• Acanthamoeba keratitis
• Corneal abrasion
• Sterile infiltrate
• Significant inflammation

A Contact Lens Safety Checklist

Before Inserting the Lenses

• Are my eyes white and comfortable?
• Have I washed my hands?
• Are my hands completely dry?
• Is the lens within its replacement period?
• Is the lens intact?
• Is it the correct lens for the correct eye?
• Is the lens clean?
• Has it avoided all water exposure?

During Wear

• Is vision clear?
• Is the lens comfortable?
• Is the eye becoming red?
• Am I approaching the recommended wearing limit?
• Am I about to sleep, shower or swim?
• Do I have spectacles available?

After Removal

For daily disposables:

• Discard the lens.

For reusable lenses:

• Rub and rinse as directed.
• Use fresh disinfecting solution.
• Never top off.
• Use a clean case.
• Complete the full soaking cycle.

Lens-Case Care

• Empty old solution.
• Rub and rinse with contact-lens solution.
• Air-dry upside down.
• Keep the caps off while drying.
• Store away from water splashes.
• Replace at least every three months.

Travel

• Pack spare lenses.
• Carry backup spectacles.
• Bring enough solution.
• Carry a spare case.
• Keep supplies in hand luggage.
• Avoid sleeping in lenses.
• Avoid water exposure.

Warning Symptoms

• Pain
• Redness
• Light sensitivity
• Reduced vision
• Discharge
• White corneal spot
• Persistent tearing

When any of these occurs:

• Remove the lens.
• Do not reinsert it.
• Seek medical advice promptly.

The Bottom Line

Contact lenses can provide safe, comfortable and effective vision correction when they are:

• Properly prescribed
• Correctly fitted
• Worn for the recommended duration
• Replaced on schedule
• Cleaned and stored appropriately
• Monitored regularly

The most important preventable risks are:

• Sleeping in lenses
• Water exposure
• Poor hand hygiene
• Reusing daily disposable lenses
• Overextending replacement schedules
• Topping up solution
• Contaminated lens cases
• Unprescribed decorative lenses
• Ignoring early symptoms

Contact lenses should never come into contact with:

• Tap water
• Bottled water
• Swimming-pool water
• Sea water
• Hot-tub water
• Saliva
• Homemade saline

Daily disposable lenses remove the need for cleaning and storage, but they are not risk-free.

Reusable lenses require:

• Rubbing
• Rinsing
• Fresh disinfecting solution
• Correct soaking
• Regular case replacement

Hydrogen peroxide solutions must be completely neutralised before the lenses are inserted.

Children can wear contact lenses successfully when they have:

• Proper fitting
• Reliable hygiene
• Parental supervision
• Regular follow-up
• Backup glasses

The most important clinical message is:

Pain, redness, light sensitivity or reduced vision in a contact-lens wearer is not normal. Remove the lens immediately and seek prompt assessment because early treatment of a corneal infection can make a major difference to the final visual outcome.

References

1. Centers for Disease Control and Prevention. Preventing eye infections when wearing contacts. Updated May 2025.
2. Centers for Disease Control and Prevention. Healthy habits: keeping water away from contact lenses. Updated May 2025.
3. Centers for Disease Control and Prevention. Cleaning, disinfecting and storing contact lenses. Updated May 2025.
4. US Food and Drug Administration. Contact lenses: important care tips.
5. US Food and Drug Administration. Hydrogen peroxide solution for contact-lens care. Updated July 2023.
6. Dart JKG, Radford CF, Minassian D, Verma S, Stapleton F. Risk factors for microbial keratitis with contemporary contact lenses. Ophthalmology. 2008;115:1647–1654. PMID: 18597850.
7. Lim CHL, Carnt NA, Farook M, et al. Risk factors for contact-lens-related microbial keratitis in Singapore. Eye. 2016;30:447–455. PMID: 26634710.
8. Booranapong W, Prabhasawat P, Kosrirukvongs P, Tarawatcharasart Y. Risk factors for contact-lens-related microbial keratitis: a case-control study. J Med Assoc Thai. 2012;95:693–698. PMID: 22994030.
9. Sauer A, Meyer N, Bourcier T. Risk factors for contact-lens-related microbial keratitis: a multicentre case-control study. Eye Contact Lens. 2016;42:158–162. PMID: 26219076.
10. Sauer A, Greth M, Letsch J, et al. Contact lenses and infectious keratitis: risk factors for wearers. Eye Contact Lens. 2020. PMID: 31990844.
11. Stapleton F, Edwards K, Keay L, et al. Risk factors and causative organisms in microbial keratitis in daily disposable contact-lens wear. PLoS One. 2017;12. PMID: 28813424.
12. Risk factors for bacterial keratitis and severe disease in hydrogel contact-lens users: a multicentre case-control study. 2024. PMID: 39252204.
13. Chalmers RL, McNally JJ, Chamberlain P, Keay L. Adverse-event rates in the Retrospective Cohort Study of Safety of Paediatric Soft Contact Lens Wear. Ophthalmic Physiol Opt. 2021;41:84–92. PMID: 33179359.
14. Li L, Moody K, Tan DTH, et al. Contact Lenses in Pediatrics Study in Singapore. Eye Contact Lens. 2009;35:188–195. PMID: 19516144.
15. Bullimore MA. The safety of soft contact lenses in children. Optom Vis Sci. 2017;94:638–646. PMID: 28514244.
16. US Food and Drug Administration. Coloured and decorative contact lenses: a prescription is a must.
17. US Food and Drug Administration. Decorative contact lenses for Halloween and other cosmetic use.
18. Centers for Disease Control and Prevention. Corneal infections associated with sleeping in contact lenses: six cases, United States, 2016–2018. MMWR. 2018.
19. Centers for Disease Control and Prevention. About contact-lens types and the importance of professional fitting. Updated May 2025.
20. US Food and Drug Administration. Buying contact lenses and maintaining a current prescription.