What type of lens causes light to converge?

A convex lens is designed to converge light rays that pass through it. This characteristic makes convex lenses essential in various optical applications, such as magnifying glasses, eyeglasses for hyperopia (farsightedness), and cameras.

When parallel rays of light enter a convex lens, they are refracted towards a focal point on the opposite side of the lens. The curvature of the lens determines the degree to which the light converges, and the focal length is the distance from the lens to this focal point. This principle is a fundamental aspect of geometric optics and is used to create images, focus light, and alter the path of light, making the convex lens vital for lenses in optical instruments. The other lens types mentioned serve different functions; for instance, diverging lenses spread light rays apart, while flat lenses and cylindrical lenses do not converge light in the same way.