Most people who wear contact lenses get years of comfortable use out of them with no real trouble. The statistics on habits, though, are worse than most wearers would guess. Roughly 99% of contact lens wearers engage in at least one risky behavior that could lead to a serious eye infection.
Contact lens-related infections affect approximately 2-20 cases per 10,000 wearers each year, and corneal infections from all causes result in approximately 1 million clinic and emergency department visits annually in the United States. Almost all of them are preventable with proper hygiene and care.
Contact Lenses and Your Corneas
Contact lenses fall into two main categories, each interacting differently with your cornea.
Rigid Gas-Permeable Lenses (RGPs)
RGPs give clearer vision and let more oxygen reach the eye. They are particularly useful for correcting vision in people whose corneas have an irregular shape. They cost more than soft lenses up front and last longer, which changes the math over a few years.
Traditional RGPs sit directly on the cornea and move a little with each blink, which lets tears get underneath the lens. Newer scleral gas-permeable lenses are more concave and considerably larger in diameter. The edge rests on the white of the eye, vaulting over the cornea entirely, so a layer of fluid stays between cornea and lens.
Soft Contact Lenses
Soft lenses are made to be thrown away after a set period, whether that is daily, biweekly, or monthly. Most people find them more comfortable and more convenient than RGPs. They may be less helpful if you have significant astigmatism.
Although the FDA has approved certain soft lenses for extended (overnight) wear, cornea specialists warn strongly against it. Overnight wear greatly increases the risk of corneal ulcer infection, which can be extremely painful and can lead to permanent vision loss.
Daily Disposable Lenses Are The Safest Option
Daily disposable contact lenses are the safest option available. You discard them each night and start fresh in the morning, which removes the lens case from the equation entirely, prevents protein buildup, and produces the lowest infection risk of any lens type.
How Contact Lenses Affect Your Corneas
Every contact lens reshapes the cornea to some degree over time. Traditional RGPs cause the most reshaping. Scleral lenses cause less. Soft lenses cause the least of the three, though none of them causes none.
The change is not permanent. Leave lenses out for a stretch and the corneas gradually return to their natural shape. That is exactly why Charlotte ophthalmologists tell patients planning cataract surgery or LASIK to stop wearing lenses well in advance. Surgical planning depends on accurate measurements of your natural corneal shape, and a warped cornea produces the wrong numbers.
Three Things You Should NEVER Do With Contact Lenses
1. Never Sleep in Contact Lenses
A thirty-minute nap is not the concern. Overnight sleep significantly increases your risk of corneal ulcer, which is the number-one reason for corneal transplants.
The mechanism is straightforward. Your cornea gets less oxygen when your eyes are closed, and a contact lens restricts that flow further. The result is an environment bacteria thrive in, and infections can cause significant vision impairment within 24 hours.
How bad it gets varies. A mild infection means temporary irritation treated with antibiotic drops, possibly leaving a small scar, and you want that scar anywhere but the center of the cornea. A severe one leaves permanent scarring, extreme pain and permanent vision loss. At the far end, corneal perforation requires an emergency corneal transplant.
2. Never Wear Lenses in Water
Don’t wear contact lenses while swimming or showering. Some water-borne bacteria, combined with lens wear, cause the most severe corneal ulcer infections there are.
Water creates other problems too. The humidity change in a shower can alter the shape of your lenses, and lenses can stick to the eye and become difficult to remove. The organism that makes this genuinely dangerous is Acanthamoeba, a parasite found in water that causes particularly devastating infections.
3. Never Handle Contacts Without Washing Your Hands
Wash your hands thoroughly before touching your lenses, and use only recommended contact lens solutions to clean and store them. Plain water is never safe for either job.
A few habits that matter more than they sound like they should: close your eyes before splashing water on your face, avoid rubbing your eyes hard at any time and especially while wearing lenses, keep tap water away from lenses and cases, and replace your contact lens case every 3 months.
Two Things Contact Lens Wearers Should Regularly Do
1. Listen to Your Body
If a lens causes irritation, take it out. Keep prescription eyeglasses on hand so you are not stuck choosing between clear vision and an uncomfortable eye. Pushing through discomfort is how minor problems become serious ones.
Warning signs requiring immediate contact lens removal
- Eye discomfort or a foreign body sensation
- Redness, especially around the cornea
- Excessive tearing
- Light sensitivity
- Eye discharge
- Blurred vision
- Severe pain
Get medical attention right away for severe eye pain, sudden vision changes, or significant redness that does not improve once the lens is out. Any of those alongside contact lens wear should be seen the same day.
2. Get Annual Eye Exams
At your annual eye exam, your doctor checks both the lenses and the corneas underneath them, looking for a prescription change and, more importantly, for problems you cannot feel yet.
Several of those are invisible to the patient. Corneal neovascularization is blood vessels growing into the cornea from excess lens wear or chronic low oxygen. Stem cell damage shows up after sustained overwear. Giant papillary conjunctivitis is inflammation under the eyelids caused by protein building up on the lenses. Corneal warping changes the shape of the cornea itself. And early infection often announces itself to an examiner well before it announces itself to you.
Doctors often steer patients toward disposable soft lenses, daily disposables in particular, when they secrete more protein in their tear film or have trouble keeping up with lens hygiene.
Corneal Ulcers Are The Most Serious Complication
Corneal ulcers represent a vision-threatening emergency requiring immediate medical attention. Knowing the risk factors is most of the prevention.
Common Risk Factors for Contact Lens-Related Corneal Ulcers
- Overnight wear or sleeping in lenses
- Extended continuous wear, meaning wearing lenses longer than prescribed
- Swimming or showering while wearing lenses
- Using expired lenses or solutions
- Storing lenses in tap water
- Poor hand hygiene when handling lenses
- Overwear, meaning too many hours per day
- Dry eye conditions
- Smoking
Most Common Infectious Organisms
CDC data shows the pathogens identified most often in contact lens-related corneal infections are Pseudomonas, the most common bacterial cause; Acanthamoeba, the parasitic infection tied to water exposure; Fusarium, a fungal infection; and Staphylococcus species.
Frequently Asked Questions About Contact Lens Safety
How long can I safely wear my contact lenses each day?
How long can I safely wear my contact lenses each day?
Most contact lenses are designed for 12-16 hours of daily wear, but individual tolerance varies. Remove your lenses earlier if you experience any discomfort, dryness, or vision changes. Never exceed the wearing time recommended by your eye care provider.
Can I reuse contact lens solution?
No. Never “top off” old solution in your lens case. Always empty the case completely, rinse with fresh solution (never water), allow it to air dry, and fill with fresh solution each time you store your lenses.
What should I do if my contact lens gets stuck in my eye?
Don’t panic. First, try rewetting drops or artificial tears to lubricate your eye. Gently massage your closed eyelid. If the lens still won’t move, don’t force it. Contact your eye care provider immediately for assistance.
Are daily disposable lenses worth the extra cost?
For most people, yes. When you consider the cost of solutions, lens cases, and the significantly reduced risk of serious infections, daily disposables often provide excellent value alongside superior safety and convenience.
Your Vision Deserves the Best Care
Worn and cared for properly, contact lenses are a safe and effective way to correct vision, which is why millions of people use them without incident. The habits above are what keep them in that category.
If you notice any sign of infection, or you have questions about how you are caring for your lenses, contact Horizon Eye Care.
