What type of lens is used to correct myopia?

A concave lens is used to correct myopia, also known as nearsightedness. Myopia occurs when the eyeball is too long or the cornea has too much curvature, which causes light rays to focus in front of the retina instead of directly on it. By using a concave lens, the light rays diverge slightly before they reach the eye. This adjustment allows the light to focus correctly on the retina, enabling clearer vision for distant objects.

Other types of lenses mentioned serve different purposes. Convex lenses are used for hyperopia (farsightedness) because they converge light rays to help focus them on the retina. Cylindrical lenses are designed to correct astigmatism, where light is focused at different points due to an irregularly shaped cornea. Bifocal lenses combine both convex and concave prescriptions to assist those who need correction for both distance and close-up vision, often in aging individuals. Each type of lens has a specific role in vision correction, highlighting the importance of selecting the appropriate lens to address particular vision issues.