Contact Lens Hygiene: How to Avoid Serious Eye Infections
Poor contact lens hygiene is the leading preventable cause of corneal infection. These evidence-based habits protect your eyes and your vision.
Updated · Dr. David Wilkinson
Contact lens-related eye infections are among the most preventable causes of vision loss in otherwise healthy young adults. Most infections result from specific, avoidable behaviours — and the habits below are the standard of care recommended by Canadian optometrists.
The core rules
1. Wash your hands before every touch
Wash with soap and water and dry thoroughly with a lint-free towel before inserting or removing lenses. This is the most important single habit.
2. Never use water with lenses or cases
Tap water contains Acanthamoeba — a microscopic organism that adheres to contact lenses and causes Acanthamoeba keratitis, one of the most painful and treatment-resistant corneal infections. Use only contact lens solution for cleaning, rinsing, and storage. Remove lenses before:
- Showering
- Swimming (pool, lake, ocean, or hot tub)
- Washing your face
3. Follow your replacement schedule exactly
Daily lenses are discarded daily. Monthly lenses are replaced after 30 days of wear. Protein and lipid deposits accumulate on lenses over time, creating a surface that promotes bacterial adherence. Wearing lenses past their replacement date is one of the most common risk factors for infection.
4. Never sleep in lenses (unless specifically prescribed for overnight wear)
The cornea receives oxygen through tears during the day. Closed eyelids during sleep reduce oxygen delivery; a contact lens reduces it further. Overnight wear multiplies infection risk 6–8 times compared to daily removal. Extended-wear lenses worn overnight still carry higher risk than daily removal — discuss this specifically with your optometrist if overnight wear is important to you.
5. Clean and replace your case properly
| Step | How |
|---|---|
| After each use | Rub with fresh solution, rinse with fresh solution, air dry face-down |
| Never | Rinse with water or top off old solution |
| Replace | Every 1–3 months, or immediately if damaged or discoloured |
The lens case is the most common source of contamination in contact lens infections.
6. Use the right solution for your lens type
Not all solutions are compatible with all lens materials. Confirm with your optometrist that the solution you use is appropriate for your specific lenses. Hydrogen peroxide systems (e.g., CLEAR CARE) require a full 6-hour neutralization cycle before insertion — inserting before neutralization is complete causes severe chemical burn to the eye.
7. Keep a backup pair of glasses
If your eyes become red or uncomfortable during lens wear, the right response is to remove the lenses and switch to glasses — not to push through the discomfort. If you do not have a current glasses prescription, you have no safe fallback option.
When to call your optometrist immediately
Remove lenses and call the same day if you experience:
- Pain or significant discomfort in the eye
- Redness that is getting worse
- Sensitivity to light
- Blurred vision
- Any discharge
Do not wait — corneal infections caused by Pseudomonas (common in contact lens wearers) can progress from minor irritation to significant corneal damage within 24–48 hours without treatment.
Contact lens hygiene and water in Ontario
Ontario municipal water meets Health Canada safety standards for drinking but is not sterile — it contains trace amounts of microorganisms including Acanthamoeba. This is safe to ingest but not safe for contact lens use. Treat all tap water as contaminated in the context of contact lens care.
Toronto Eye Care
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Book an appointment →Frequently Asked Questions
- What is the most serious risk of wearing contact lenses?
- Microbial keratitis — a bacterial, fungal, or parasitic infection of the cornea — is the most serious complication of contact lens wear. Pseudomonas aeruginosa and Acanthamoeba are particularly dangerous organisms. Severe cases can cause permanent corneal scarring and vision loss requiring a corneal transplant. The risk is significantly reduced with proper hygiene.
- Can I shower or swim in contact lenses?
- No. Tap water, lake water, pool water, and even distilled water can contain Acanthamoeba — a microscopic organism that causes a painful, difficult-to-treat corneal infection. Contact lenses should be removed before any water exposure including showering, swimming, and using hot tubs.
- How should I clean my contact lens case?
- Rinse the case with fresh contact lens solution (not water) after each use, rub the inside with your finger, and leave it face-down on a clean tissue to air dry. Replace the case every 1–3 months. Never top off old solution — always discard residual solution and refill with fresh product.
- Is it safe to nap in contact lenses?
- Sleeping in contact lenses — even briefly — significantly increases infection risk because blinking stops and the cornea receives less oxygen. Remove lenses before any sleep. If you occasionally fall asleep in lenses, remove them as soon as you wake, give your eyes a break with glasses, and use lubricating drops if needed.
- What are the signs of a contact lens-related eye infection?
- Warning signs include: increasing redness especially around the cornea, eye pain or significant discomfort (beyond normal end-of-day dryness), sensitivity to light, blurred vision that does not clear, and discharge. Remove your lenses immediately and see your optometrist the same day — corneal infections progress rapidly and require prompt antibiotic treatment.
Author
Dr. David Wilkinson, OD, FAAO — Pending clinical review
Optometrist, Spadina Optometry
A Toronto native and Fellow of the American Academy of Optometry, Dr. David Wilkinson has been part of our optometric practice since earning his OD from the Illinois College of Optometry in 2007. A certified clinical investigator with a special interest in contact lenses and myopia management, he serves as a part-time Clinical Instructor at the University of Waterloo's Waterloo Eye Institute and previously spent nearly a decade as Practice Advisor at the College of Optometrists of Ontario.