Corneal arcus generally appears in older people, which is why it’s also called arcus senilis. Arcus senilis is a circular ring in the periphery of your cornea made up of cholesterol deposits. A flaxen or gray-colored band forms, circling the cornea of each affected eye. This opaque halo surrounding your cornea’s stromal layer has a distinct border on the outside while the inside border is less defined.
The material is made of an abnormally high level of phospholipids and cholesterol deposits. The phospholipid sediments of the corneal arcus generally start at the bottom and the top of your cornea. However, these deposits can eventually expand to completely cover the entire circumference of your cornea, which is usually when you start having vision problems.
The condition affects about 60 percent of the population between 50 and 60 years old. For persons over the age of 80, corneal arcus afflicts nearly 100 percent of those tested. The incidence is even higher in the African American population, although researchers aren’t sure why.