Contact Lenses Work: How It Works, Explained Simply

Video Transcript

A contact lens is a thin, curved lens that rests directly on the tear film covering your cornea. It corrects vision the same way glasses do, by bending light so it focuses on the retina. The difference is that it sits on the eye itself. It does not touch the eye directly. A microscopically thin layer of tears sits underneath, and the lens moves slightly with every blink. Most people wear soft lenses, made of flexible water-containing materials that let oxygen reach the cornea. Rigid gas permeable lenses are smaller and firm. They hold their shape, which can give sharper vision for irregular corneas. Soft lenses come in daily disposables, which you throw away each night, and reusable lenses replaced every two weeks or monthly. There are also toric lenses for astigmatism, multifocal lenses for reading, and large scleral lenses that vault over the cornea for conditions like keratoconus. Contact lenses are medical devices and need a proper fitting. Your eye's curvature and size are measured, so a glasses prescription alone is not enough. This video is for general education only. It is not medical advice. Ask your eye doctor what's right for you.