The prevalence of hyperopia is less compared with myopia. The level of hyperopia is usually between +1 to +4 diopters, and it is rarely equal or greater than +8 diopters. Hyperopia occurs when either the eye has a shorter length compared with the corneal curvature, or the cornea is of lesser curvature compared with the ocular length, and as a result, the light entering the eye is focused behind the retina. In this case, far objects appear blurry, and close images seem even blurrier. Using the focusing power of the eye’s natural lens, young people with hyperopia can take the image from behind the retina back on to the retina, and as a result they can see clearly. But in severe hyperopia or at older ages this ability is reduced, and patients need reading glasses or bifocals.
As age increases, the ability of the natural lens of the eye to focus images on the retina decreases, so people with hyperopia gradually become more dependent on glasses, and they need higher power prescriptions. The real optical power that a hyperotic person needs to correct his/her vision is usually greater than his/her prescription power. In order to correct hyperopia, convex lenses are used, indicated by a positive (+) sign. These glasses make eyes look bigger.