<prompt> A 35-year-old Insulin Dependent Diabetes Mellitus IDDM patient on Insulin for the past 10 years com- plains of gradually progressive painless loss of vision. Most likely he hasCataractVitreous haemorrhageTotal rhegmatogenous retinal detachmentTractional retinal detachment not involving the macula  <response>: 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. 