What Sleeping With Contacts Really Does to Your Eyes

Spoiler: don't do it.
Contacts case and glasses on turquoise background.
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If you’re a regular contact wearer, chances are you’ve fallen asleep in your contacts at some point in time (or maybe even a few times). We all know sleeping with contacts is not recommended by eye doctors, but why, exactly? What’s actually happening in your eyes when you sleep with your contacts in?

To find out, we had to get a little familiar with how daily contact wearing actually affects your body. As with any foreign object or substance that you introduce to your body, whether it be a food or a drug, contacts take some time to get used to. “The FDA actually describes contacts as a drug,” says Russell Wohl, OD, from Farmingdale, New York. “No you’re not ingesting a contact, it’s just sitting on your eye, but your body has to get acclimated to it.” Each individual’s tears are made up of a certain pH acidity, explains Wohl, and when you put a contact into your eye, the contact solution—not the actual lens—has a different pH. This is what sometimes causes burning or tearing when you put your contact in.


So, what happens when you sleep with contacts?

When you sleep, your eyes miss out on ambient oxygen exposure—a key component of keeping eyes healthy. “What a contact lens does is limit the oxygen even more because it creates a barrier between the oxygen and the cornea,” explains Wohl. “Some lenses—extended wear ones—allow the oxygen though,” says Wohl, but if not enough oxygen gets through, you can experience what is called hypoxia (oxygen deprivation in a region of the body).

You also increase your chances of developing an infection. When your eyes are closed, bacteria can get onto the cornea and get lodged there, since, there’s nothing to flush it away. “The bacteria can then become opportunistic and literally start to eat away at your cornea,” says Wohl. “Worst case scenario from that is loss of vision.”

What if you accidentally fall asleep with your contacts in?

If you fall asleep with your lenses in for just one night, it's not the end of the world. But if it becomes a more frequent habit or you’re purposefully wearing lenses overnight that aren’t mean to be, you’re upping your chance of a serious health risk.

