45 million Americans could be putting themselves at risk for permanent eye damage — and it's largely preventable

contact lens, eye

When people ask me why I don't wear contacts, I typically come up with some excuse to avoid admitting the truth: Sticking a plastic device directly on the fragile mucous membrane surrounding my cornea terrifies me.

But it does, and it's the reason I've always felt A-OK just wearing glasses.

A new report from the Centers for Disease Control and Prevention makes me feel slightly justified in my fear of contacts, despite the fact that they're largely safe and effective — at least when worn correctly.

The report builds on previous findings from 2015, when the CDC found that more than 99% of the contact lens wearers they surveyed reported at least one behavior that put them at risk for an eye infection. Forty-five million Americans don't share my fear, opting to use contacts on the regular.

According to the new study, which surveyed roughly 4,500 adults and 1,600 adolescents aged 12–17 years, six out of every seven people who wear contact lenses engaged in at least one habit that put them at risk for a serious contact lens–related eye infection last year. Across age groups, the most common risky habits included sleeping, napping, or swimming in contacts and failing to replace lenses and lens storage cases when needed. Among adolescents, the most common was failing to see an eye doctor every year.

Why forgetting to replace your contacts is dangerous

When you don't replace contact lenses and their cases as often as recommended, it raises the chances of developing an infection for several reasons.

woman swimming swim underwater pool First and foremost, every time you touch your lenses, you're opening up the possibility of introducing microbial life onto the contact. Because the lenses are already moist — just like your eyes — they're already ripe terrain for bacteria to take hold. So long as you always wash your hands and swap your lenses on the regular, these microbes don't have too much time to blossom into veritable forests of bacteria. But when you get sluggish about replacing them and continue using and re-using the same old lenses, you're increasing the chances that all that bacteria will start to proliferate and infect your eyes.

It's no surprise then that people who don't swap out their lenses frequently report more complications and more eye discomfort.

Exposing contacts to water — whether it's your gym pool or some tap water — can also heighten your infection risk. Water is home to all kinds of microorganisms, and those can easily be transferred to the eye.

Last year, roughly 1 in 5 of all of the contact lense-related infections reported to the CDC included someone who had scarred their cornea, needed a corneal transplant, or had reduced vision. The cornea, the eye's clear front dome, plays a key role in vision and has a remarkable capacity to recover from most minor nicks. But an infection — like the ones described in the CDC's report — can damage the cornea's deeper layers, making it tough to completely heal.

In some cases, corneal damage can also cause scarring, which can distort your vision. When the scarring is severe, you may need a corneal transplant, which involves swapping part of your cornea with tissue from a donor.

How to keep your eyes healthy

While these problems sound severe, most of them are potentially preventable.

"Prevention efforts should focus on encouraging contact lens wearers to replace their contact lens storage case regularly and to avoid sleeping or napping in contact lenses," the authors of the report wrote.

Here are some other easy ways to keep your contacts — and your eyes — clean and healthy:

1. Wash your hands before handling your lenses.

2. Completely replace yesterday's contact solution.

3. Wear your contacts for only as long as they're prescribed.

4. Rinse your lens case with contact solution and wipe it out with a clean towel after every use.

Finally, next time you get up to put on your contacts, remember — you're putting in a medical device. Handle it with care.

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