Ophthalmology is the branch of medicine and surgery concerned with diseases of vision and the eye. In infancy, congenital blindness and strabismus, and in adults, glaucoma, uveitis, cataract, retinal detachment, and vascular diseases are common, as are ocular manifestations of systemic diseases – hypertension and diabetes. Disorders of eye movement, lids, and tear production; color vision; infection, and injury are also seen. Surgery to the lens, cornea (including corneal grafting), eye muscles, and lids may be used, and cryosurgery (freezing) or coagulation employed in retinal disease.