Myopia (nearsightedness) is a vision condition in which people can see close objects clearly, but objects farther away appear blurred. It is typically corrected with glasses or contact lenses, and the majority of cases are classified as mild.
High degrees of myopia are called degenerative or pathological and occur in one to nine percent of adults throughout the world. In myopia, the eye is too long and focuses light in front of the retina. Because the eyeball is elongated, tissue, including the retina, is stretched and thinner than normal. In degenerative myopia, this gradually damages the retina, choroid, vitreous, sclera and optic nerve. It is not related to ordinary myopia and does not develop from it.