Refractive Errors

Refractive errors are the most common eye; the image of the object a person is looking at is not focused properly onto the retina (the light-sensitive tissue in the back of the eye). This happens when there is a mismatch between the length of the eye, and its optical power. It is said that these mismatches usually originate during childhood, when the eyes are growing, but nevertheless the exact causes are still being studied.
Refractive errors can usually be corrected using spectacles or contact lenses, though there are also surgical techniques to correct refractive errors.

Refractive errors: The shape of the eye doesn't refract, or bend, light properly, so images appear blurred.

Types:

There are four main types of refractive errors - Myopia (shortsightedness), Hyperopia (longsightedness), Astigmatism and Presbyopia.