A contact lens is a thin lens placed directly on the surface of the eye.
People choose to wear CLs for many reasons. Aesthetics and cosmetics are the main motivating factors for people who want to avoid wearing glasses or to change the appearance of their eyes. Others wear CLs for functional or optical reasons. When compared with spectacles, CLs typically provide better peripheral vision, and do not collect moisture (from rain, snow, condensation etc.) or perspiration; this makes them ideal for sports and other outdoor activities