These types of lenses have been approved by physicians and the FDA for overnight wear. This is because these varieties of lenses allow more oxygen to reach the eye. This is good for many reasons. Eyes do not dry out so much as they do with lenses that are not breathable, meaning that sleeping in your lenses causes less pain and irritation. The added oxygen helps your eyes defend themselves from bacteria, and it makes the eye environment a little less friendly to bacteria growth. 

For many years contact lens wearers felt perfectly safe to sleep in their extended-wear lenses. More recent medical studies have proven, though, that this practice is not as risk free as it was once imagined to be. In spite of the fact that extended-wear lenses are more breathable, they still create a moist, warm environment over the eye. This makes wearers particularly susceptible to dangerous eye infections. Overnight lens wear is the number one cause of infective corneal ulcers, a dangerous condition that could even lead to losing your eye. Studies have found that the type of extended-wear lens that you use could raise your chances for this threat. Although sleeping in hydrogel or silicone hydrogel lenses can both cause infections, those who wear hydrogel lenses are at a far greater risk for these issues. Many eye specialists advise patients to take their lenses out before bed, even if they are using extended-wear varieties. Sleep in these lenses on occasion, rather than every night, if you must sleep in them at all. 

Even though it is a pain to remove your lenses each night, you should try to make this common practice. If you are the type who needs a night off from lens care every now and then, choose a silicon hydrogen extended-wear lens, and be sure to take them out before bed as often as possible. 

This is a guest-post by Ashley Williamson. Ashley is a part time guest blogger and a full time health specialist currently writing for OZmattress where you can find great deals of mattress sale online.