To prevent farsightedness, we use

Farsightedness, also known as hyperopia, is a common vision condition where distant objects are seen more clearly than near ones because the eye focuses light behind the retina rather than directly on it. The correct answer is [C] Convex lens. To correct this condition, convex lenses are used. Convex lenses, also known as converging lenses, have a shape that is thicker at the center and thinner at the edges. They work by converging light rays before they enter the eye, helping to shift the focal point forward so that it falls directly on the retina. This adjustment allows individuals with hyperopia to see nearby objects more clearly. Convex lenses are commonly used in eyeglasses and contact lenses prescribed for people with farsightedness. Concave lenses, convex mirrors, and concave mirrors are not suitable for correcting farsightedness, as they have different optical properties and are used for different purposes in vision correction and optics.