Arcus senilis (or arcus senilis corneae) is a white or gray, opaque ring in the corneal margin (peripheral corneal opacity), or white ring in front of the periphery of the iris. It is present at birth, but then fades; however, it is quite commonly present in the elderly. It can also appear earlier in life as a result of hypercholesterolemia. Arcus senilis can be confused with the limbus sign, which reflects calcium rather than lipid deposits.