What is refraction error?
Myopia, hyeropia and astigmatism are different types of eye disorders, or refractive errors. In the normal eye, light enters through the front of the eye at the cornea and is directed to a single point at the back of the eye on the retina. In an eye with a refractive error, the light is not directed to a single point to the back of the eye but in front of the retina. This is known as myopia or nearsightedness. When the light is directed to a point behind the retina, the refraction error is known as hyperopia or farsightedness. The refractive error known as astigmatism occurs when the light is sent to two points behind, in front of or on the retina.