Myopia- or near-sightedness is the ability to clearly see objects up close like a book or newspaper but not those in the distance, which could create problems for a patient while driving a car or in other activities. It is found to be mainly a hereditary condition usually manifesting itself between the ages of eight and twelve.

The best treatment is usually with eyeglasses or contact lenses which allow light coming through the cornea and lens to be refracted onto the retina at the proper place by compensating for the elongated shape of the eye. LASIK is available as a treatment, but should be preformed in adulthood when typically the condition has leveled off.

Hyperopia- or farsightedness is when distant objects are seen clearly, but objects close to the face are blurred. The light rays again are not focused on the retina properly but this is caused by the eyeball being not elongated enough or from the lens having too high of a refractive power. While it is often inherited, it may develop as a patient ages since the elasticity of the eye may diminish. This can also be corrected by glasses, contacts or LASIK.

Astigmatism is a distortion in vision caused by an irregular curvature of the cornea of the eye or the lens. When light passes through the eye, the rays are not focused correctly on the retina at the back of the eye. This would cause blurry vision. Astigmatism can be compensated for by eyeglasses or contact lenses or LASIK.