Treatment
Refractive errors of the eye such as myopia, hyperopia, astigmatism, and presbyopia can all be corrected
with eyeglasses. Contact lenses, both soft and hard, can also be used to correct
refractive errorsÑincluding aphakia, a condition that most commonly follows the removal of a lens during cataract surgery, if a lens implant is not put in the eye.
Surgical
procedures on the cornea to correct for myopia, astigmatism, and less commonly hyperopia are becoming popular. These procedures include radial keratotomy, which employs a diamond knife, and laser procedures such as cornea sculpting, or photo-refractive keratectomy. An opacified or markedly damaged cornea now can be replaced, and eye banks have been established for the provision of donor material in cases where corneal transplantation is required.
Scientists have been able to isolate the genes that cause many eye diseases. For example, the gene associated with retinoblastoma has been identified. Research on the various eye defects and diseases is conducted by the National Eye Institute and other organizations. Ophthalmologists are physicians who treat all types of eye diseases and perform surgery. Optometrists can prescribe glasses, contact lenses, and medications for some visual defects.