Contact lenses are corrective plastic discs that are inserted on the eye's cornea to correct the wearer's vision. In some instances, people use contact lenses for cosmetic purposes, such as changing their eye color from, for example, gray to blue. Contact lenses have the same function as eyeglasses. Unlike eyeglasses, however, they are worn directly on the eye, are lightweight and almost invisible. Some side effects are occasionally associated with use of contact lenses.Contact lenses have become a welcome alternative to wearing prescription eyeglasses. But, concern has grown over the years about long-term contact use and its effects on overall human health
For those who have eyesight problems, contacts can help to clear vision by adhering to the outside of the eye, typically during the hours a person is awake. You can wear other contacts, such as extended-wear types, while sleeping.