ABSTRACT
The eye is made up of highly specialized and complex groups of tissues that are important to vision. Visual impairment can result from severe damage to the cornea, lens, nerve tissue of the eye, optic nerve, retina, or the brain. Central visual disturbances usually involve macular atrophy and change in the vitreous and aqueous humor, complications that often lead to a complete loss of vision. While cataracts and corneal opacity account for most cases of blindness in developing countries, degenerative diseases of the retina are the leading cause of blindness in the Western world.
