What is "arcus senilis"

n. A faint whitish ring around the iris in elderly people; discoloration of the iris with age.

n. an arc-shaped whitish deposit sometimes seen in the cornea [syn: arcus]

Arcus senilis (or arcus senilis corneae) is a white, grey, or blue 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.