Overview of Refractive errors

Overview:

In normal vision, light rays from an object focus on the retina (emmetropia). Alternatively, in the presence of a refractive error, the light rays get focused in front or behind the retina causing blurred vision. Under normal conditions, as the eyeball grows in size from infancy to adulthood, there will be a corresponding change in curvature of the cornea and the lens enabling the eye to remain emmetropic, at all ages. When one of these fails to happen, refractive error occurs.