You are probably not going to be surprised when I tell you this is one of the most common questions patients ask on a daily basis. You are also probably not surprised that this is one of the biggest reasons a patient will have to be seen for a new onset “red eye” appointment!
Let’s begin with the simple answer: You have less of a chance of contact lens related complications by NOT sleeping in your contacts (this includes naps). However, there are certain brands of contacts that are approved to be slept in. If you tend to overwear your contacts, nap in them, or sleep in them, it is paramount that you are fit for an extended wear contact lens.
That being said, just because a contact lens is approved to sleep in, does not mean EVERYONE CAN actually sleep in them with comfort and no complications. The main reason is a contact lens acts as a barrier to oxygen entering your eyes and letting the cornea breath. When your eyes are open, there is an abundance of oxygen and we tend not to have issues (some patients report dryness to tired, red eyes at the end of the day, which may mean you need a different lens type). However, when you close your eyes for a nap or sleep, oxygen from the blood vessels is in the back of your eyelid give the cornea oxygen. If you have a contact lens that does not transmit properly, you will suffocate the cornea and can get an infection.
In simpler terms, how long can you hold your breath? Well, you are asking the cornea to do that all night if your contact does not let enough oxygen through. To reduce the most risk, do not sleep or nap in lenses. And if you do, make sure you have a breathable lens approved for those situations.