Arcus senilis is a common eye condition characterized by a gray or white arc that appears around the cornea, the clear front part of the eye. This arc is caused by the deposition of lipids, or fats, in the outer edge of the cornea. It is most often seen in older adults, but can occasionally occur in younger individuals with certain health conditions. While arcus senilis itself is usually harmless and does not affect vision, it can be a sign of underlying health issues, particularly related to cholesterol levels. Regular eye examinations can help monitor this condition and ensure overall eye health.