Wearing Contact Lenses While Sleeping? Why That's A Bad Idea

So you dozed off without removing your contact lenses. Even though we are adequately warned against doing this, it remains one of the most commonly reported behaviors among teenagers and adults who use contacts. 

It looks like a lot of us underestimate how dangerous the habit can be. "It's like having a plastic bag over your head when you sleep," said Dr. Rebecca Taylor, M.D., an ophthalmologist in private practice in Nashville, Tennessee. "It's not ideal for oxygen exchange."

The science is pretty simple and has a lot to do with the cornea — this is the outermost, transparent layer of your eye. When you are awake, the cornea receives oxygen via direct contact with the surrounding air. 

So every time you close your eyes during sleep, the oxygen supply is reduced since your eyelid acts as a barrier. But when you fall asleep without removing your contact lenses, these devices can end up being an additional barrier.

Without enough O2, the cornea tends to experience some degree of swelling and may end up with tiny cracks on the surface. This raises the risk of bacteria possibly sneaking through those gaps and leading to an infection. There are many risk factors involved here such as how often you fall asleep with your contacts in, the duration of your sleep, etc.

For example, as contact wearers may know, getting drunk involves a higher risk of passing out with your contacts in. But in addition to that, you are also more prone to an infection thanks to the dehydrating effects of alcohol.

Overnight use of contact lenses, even occasionally, can make you 6.5 times more likely to suffer from keratitis, which is the inflammation of the cornea. In less severe cases, this can usually be healed by not wearing contacts for a while.

"But if an infection develops, it can cause a corneal ulcer. It starts to get eaten away or eroded by microorganisms," NYC-based Andrea Thau, O.D., told SELF. Here, the worst case scenario can mean losing an eye.

If you accidentally fell asleep with your contacts in, you don't have to panic. Just watch out for possible symptoms of an infection. For instance, red eyes, watering, and discharge indicate that you should get them checked out by a doctor.

Of course, another sign is problems with the quality of vision. As Glamour notes, you may be experiencing an infection if looking at an indoor lamp makes you feel like you are directly looking at the sun.

Though there are FDA-approved contact lenses that can be worn for extended periods, experts recommend being on the safe side as much as possible. "Even contact lenses that have extended wear should be removed regularly, at least once a week, to lessen the chances of corneal infection," optometrist Andre Horn cautioned.