Some older people have a grey ring at the outer edge of their corneas, called a “corneal arcus,” that usually develops symmetrically but may begin as an incomplete ring. It can be yellow, white, or gray in color and is composed of lipids (fats) that have infiltrated the cornea. While this cloudy ring at the periphery of the cornea does not generally affect vision, it may be indicative of raised cholesterol levels. In fact, about half of those with this gray band on the outer edge of their corneas do have high cholesterol, but only a blood test can confirm this diagnosis. When detected, therefore, a referral to a physician for a cholesterol blood test is recommended.
P.S. Corneal arcus is present at birth but eventually fades.