The reason for vision lensesâ€™ effectiveness in correcting refractive errors lies in that these problems are commonly linked with an irregular eyeball or lens. A natural, healthy lens is capable of focusing the light entering the eye properly on the retina. However, a myopia or hyperopia eye has an abnormal shape, which can no longer focus the light as needed. Placed before the eyes, vision lenses are just supposed to help focus the light properly, and thus the wearer can see images clearly.
Nearsighted individuals cannot clearly see things that are distant. This happens because the light rays come into focus in front of the retina. Farsighted individuals have the opposite problem. The shape of their eyes causes the light rays to come into focus behind the retina, causing things that are near to them to be out of focus. Some people have blurry vision due to an astigmatism, or a condition where the curvature of the eye is irregular, creating a second focal point within the eye. All three of these common problems can be corrected with glasses.
Eyeglass lenses are curved pieces of glass. The curvature of the lens bends the light rays as they approach your eye. This helps the rays focus on your retina, instead of behind or in front of it.