What type of vision correction is achieved with a convex lens?

A convex lens is primarily used to correct hyperopia, also known as farsightedness. In hyperopia, distant objects may be seen clearly, but near objects appear blurry because the eye is either too short or the cornea has too little curvature. The convex lens helps by converging light rays before they enter the eye, effectively allowing the light to focus on the retina rather than behind it. This adjustment improves clarity for nearby objects.

While other conditions such as myopia (nearsightedness) and astigmatism (where vision is distorted due to an irregular shape of the cornea) require different types of lens corrections, the convex lens specifically addresses the need for hyperopia. Presbyopia, a condition associated with aging that affects the eye’s ability to focus on close objects, can also be corrected with convex lenses, but this is generally considered a specific use of them due to the natural change in the eye rather than the primary purpose of the lens itself. Thus, while presbyopia can benefit from convex lenses, the direct correction function for hyperopia is the most fundamental aspect of their design.