Corneal ulcer

These days, contact lenses are designed to be more comfortable and wearable, but it’s still important to follow the guidance outlined by the manufacturer and delivered by your eyecare professional. There are several habits that contact lens wearers should aim to avoid, and sleeping with your contact lenses in is just one of them.  

This is because the tissues of your eyes need oxygen in order to function properly.  

When you're awake, your open eye gets oxygen from your tears and the air. When you’re sleeping, your eyelids are closed and therefore less oxygen is transmitted to your cornea from the surrounding air. If you still have your contact lenses in, this prevents even more oxygen from reaching your eye because the plastic acts as a physical barrier. When the eye doesn't receive enough oxygen, a condition called corneal neovascularization may develop where abnormal, small blood vessels grow in the cornea in order to provide oxygen supply to the area.   

Aside from this condition, sleeping with your contact lenses in can also lead to eye redness, strain, or pain, and increased sensitivity to light. The lens itself may tighten while on the eye, which can result in small scratches on your cornea (the front surface of your eye). This may increase the risk of an eye infection or inflammation. For these reasons, it's important that you never sleep with your contact lenses in, no matter the type of lens. There are some types of lenses that have been specifically designed for overnight or extended wear, but you should discuss your options with your optometrist to see if they might be right for you.