Causes of a Ring Around the Cornea

Some people develop a gray, white, or bluish circle around all or part of the colored part of the eyeball (called the cornea). Sometimes referred to as a "ring around the pupil," the condition is officially known as corneal arcus. It can also be referred to as arcus senilis in older people and arcus juvenilis in younger people.

Corneal arcus may appear as an arc above or beneath the cornea, or it may form an entire ring around the cornea. While it is often considered benign, particularly in the elderly, evidence suggests that if may predictive of heart disease in younger people.

Arcus senilis is common among elderly people. The whitish arc is caused by the deposit of fat (lipids) around the cornea. The condition is typically associated with higher cholesterol levels. Discoloration caused by arcus senilis does not decrease vision or harm the eye.

Corneal arcus is more prevalent in men than in women and in blacks than in whites. Its prevalence increases with advancing age. It is associated with hypercholesterolemia, alcohol, hypertension (high blood pressure), smoking, diabetes, age, and coronary heart disease.

With that being said, the appearance of arcus senilis over the age of 50 is not inherently linked to an increased risk of disease. Rather, it tends to mirror the expected rate of hypertension, diabetes, and coronary heart disease in people of that age group.

While considered relatively benign in older adults, most ophthalmologists will recommend that people under 50 with corneal arcus should have their blood tested to check for hypercholesterolemia (elevated cholesterol levels) and other lipid-related abnormalities.

Research has shown that younger people, especially men, with corneal arcus tend to have a higher risk of coronary heart disease (CHD) or cardiovascular disease (CVD).

Moreover, by the age of 64, the study predicted that this same group of individuals would not only have excessively high LDL levels (154 mg/dL) but high triglycerides (115 mg/dL), high total cholesterol (232 mg/dL), and a high systolic blood pressure (138 mm Hg).

All of these factors are highly predictive of CHD and CVD.

Arcus senilis is essentially a harmless condition in older people. So, too, are other changes in eye color. For example, a baby's eye color can change and change again until they are up to three years of age. 

Other changes in eye color should be checked out by your ophthalmologist. For example:

• If the whites of your eyes have turned yellow, you may be suffering from jaundice, a condition associated with liver problems.
• Yellowish eyes may be also be related to a subconjunctival hemorrhage, a condition symptomatic of diabetes, hypertension, or even leukemia.
• Red spots could be a symptom of sickle cell disease or a benign or cancerous tumor.
• Conjunctivitis ("pink eye") is a highly contagious infection of the eye that can cause itching and pain.
• A whitish cast over the eye is usually the sign of cataracts.

It is also physically possible to permanently change the color of your eyes. This can be accomplished through surgery or a corneal transplant.