(A) Cataract> Patients present with chronic, slowly progressive and generally painless visual loss. The reduction in vision is usually bilateral, though frequently asymmetrical, and occurs over weeks to years.> More common conditions that cause gradual loss of vision can be divided into two groups based on the reversibility of the visual loss.> Cataracts, refractive error, corneal blindness and early diabetic macular edema are generally reversible.> Optic atrophy, glaucoma, retinal degeneration and age-related macular degeneration usually cause permanent loss of vision.> Senile cataract occurs early and more frequently in diabetics.