Which type of lens is primarily used to correct nearsightedness?

The type of lens primarily used to correct nearsightedness, or myopia, is the concave lens. Nearsightedness is a condition where distant objects appear blurry while close objects can be seen clearly. This occurs because the light rays entering the eye converge before they reach the retina, causing the images of distant objects to be focused in front of it.

Concave lenses are thinner at the center and thicker at the edges. When a concave lens is placed in front of a nearsighted individual's eye, it diverges the light rays before they enter the eye, effectively allowing the rays to spread out. This adjustment enables the light rays to reach the retina accurately, resulting in a clearer vision of distant objects.

In contrast, other lens types serve different corrective purposes. Convex lenses, for example, are used to correct farsightedness (hyperopia) where distant objects are seen clearly but close ones are not. Flat lenses do not alter the pathway of light and thus have no corrective power. Aspheric lenses are designed to reduce distortion in vision and can be beneficial in correcting certain vision problems, but they are flexible in their design rather than specifically addressing nearsightedness. Therefore, the concave lens is specifically tailored to meet the