Definition
Arcus senilis is a gray or white arc, circle, or ring around the cornea of the eye. It is a common age-related change, typically caused by the deposition of lipids (fats) in the peripheral cornea. Visualize it as a hazy halo around the colored part of the eye. While usually benign in older individuals, its presence in younger people can indicate elevated cholesterol levels. It doesn't typically impair vision, but should be evaluated by a physician to rule out underlying metabolic disorders, especially if it appears prematurely. The term refers specifically to this phenomenon occurring with age.