Diabetic Cataracts

Diabetic cataracts describe a clouding of the lens inside the eye that can develop in dogs with diabetes mellitus. The lens normally remains clear by carefully regulating the glucose and water content inside it, but when blood glucose stays elevated, the lens swells and its fibres become disorganised, leading to opacity. This process can unfold quickly—sometimes over days to weeks—and may affect one or both eyes. Owners often notice a change in the appearance of the eye itself: the pupil may look grey, white, or milky rather than black, and the dog may begin bumping into furniture, hesitating on stairs, or seeming uncertain in dim light or unfamiliar spaces. In some cases the change is sudden enough that the dog appears almost entirely unable to see within a short window of time. This page explores what signs tend to appear and when, what is happening inside the eye as the cataract forms, how the condition is assessed, and what approaches exist for managing both the cataract and the diabetes that underlies it.