Nearsightedness, or myopia, as it is medically termed, is a vision condition in which close objects are seen clearly, but objects farther away appear blurred. Nearsightedness occurs if the eyeball is too long or the cornea, the clear front cover of the eye, has too much curvature. As a result, the light entering the eye isn’t focused correctly and distant objects look blurred.
Short sight, clinically referred to as Myopia, is when objects are seen more clearly close up than those in the distance.
People who suffer from short sight can often carry out close work, such as reading, comfortably but find it difficult to see things in the distance, making things like driving or watching television uncomfortable.
Myopia is caused by a variation in the shape of the eyes – namely the eye being too long from front to back, or the power of the cornea or lens being too strong. The result is a mismatch between the length of the eye and its focusing power. Therefore the light rays do not reach the retina and images are not seen clearly.
The cornea, the clear window at the front of the eye, accounts for up to 80% of the focusing power of the eye. It is this part of the eye that can be altered through laser eye surgery to alter the refractive properties of the eye and thereby reduce the myopia in the eyes.