Should you sleep in contacts?
The short answer is NO. The longer answer is also NO. Even contact lenses that are labeled as "extended wear" or marketed as ok to sleep in by the manufacturer should be taken out at night. Over-wearing contacts can lead to serious corneal infections and permanent loss of vision. In fact, sleeping in contacts increases your risk for eye infections by six-eight times the normal rate!! The risk for infections come from the fact that contact lenses collect all kinds of germs and debris during the day. The longer that bacteria and debris sit on the eye, the more likely it is to cause an infection. The cornea (the part of the eye the contact sits on) can scar with severe enough infections. That scarring is what causes permanent vision loss.
Tips to avoid contact lens related infections:
Rub lenses when cleaning them. Wash your hands before cleaning your contacts. Place the lens in your clean palm with fresh solution. Rubbing the lens as you clean it loosens the protein and bacteria that builds up. Even if your solution says "No Rub," you should do it anyway. Studies have proven that rubbing the lenses is one of the best ways to avoid eye infections.
Rinse lenses with fresh solution. Always rinse and store your contact lenses in fresh solution. Never reuse the solution from the previous day.
Replace your contact lens case with a new one at least three times per year.
Periodically, give your eyes a break from your contact lenses. Wear your glasses for an entire day once a month . Also, never sleep in your contact lenses. That makes it much more likely for you to get an eye infection.
Replace the contact per manufacturer/doctor recommendations. Don’t try to extend the life of your contacts by wearing them too long. Only keep lenses as long as your doctor recommends. For example, one-month contact lenses should only be used for 30 days after opening the package.