Arcus senilis is the appearance of a white, light grey, or blueish ring around the edge of the cornea. It is made of fatty substances (called lipids), mostly cholesterol. The cornea is usually clear and allows the color of your iris beneath it to show through. This ring will make your iris has two different colors, but it is a discoloration in the cornea.
This condition is commonly seen in older adults. Arcus senilis does not affect vision and it also does not require treatment.
When arcus senilis occurs in older adults, it is not related to high cholesterol. However, an arc or ring around the iris sometimes occurs in younger people who have familial hyperlipidemia. In people with familial hyperlipidemia, this arc or ring typically occurs before age 45 and is linked to an increased risk of heart disease.