Corneal arcus is a white, blue, or gray ring of fatty deposits that forms around the outer edge of your cornea, the clear front surface of the eye. It typically starts as a crescent-shaped arc at the top and bottom of the cornea before eventually curving all the way around to form a complete ring. The condition causes no pain and no vision loss. Its significance depends almost entirely on your age when it appears.
What It Looks Like
The ring is opaque and sits right at the border where the colored part of your eye (the iris) meets the white. A thin sliver of clear cornea, called the lucid interval of Vogt, separates the ring from the very edge of the cornea. That clear gap is one way eye doctors distinguish corneal arcus from calcium deposits in the cornea, which can look similar but sit in a slightly different position.
In its early stages, you might notice a faint arc only along the top or bottom of the cornea. Over time, those arcs can extend and connect into a full circle. The color ranges from whitish to bluish-gray, and the ring tends to become more prominent with age. Many people never notice it themselves; it’s often spotted during a routine eye exam.
How Lipid Deposits End Up in the Cornea
The ring forms when lipids, primarily cholesterol and related fats circulating in your blood, leak out of tiny blood vessels at the edge of the cornea. These limbal vessels are the only blood supply near the cornea, and researchers believe that as they become less competent over time, fats seep into the surrounding corneal tissue and accumulate. The cornea itself has no blood vessels, so once lipids settle there, the body has limited ability to clear them out.
Higher levels of circulating cholesterol appear to accelerate this process. When new or abnormal blood vessels form near the cornea, they tend to be especially leaky because they lack the tight junctions and structural support of mature vessels, allowing even more lipid to pass through.
Why Age Matters
In older adults, corneal arcus is extremely common and usually harmless. A large study of adults 60 and older in Tehran found that about 34% of people aged 60 to 64 had it, rising to roughly 52% by age 70 to 74 and 56% in those 80 and older. Another study in Iran found a 23% prevalence among people aged 40 to 65. Given these numbers, arcus in someone over 60 is considered a normal part of aging.
The picture changes in younger people. When corneal arcus appears before age 50, it raises a red flag for abnormal lipid metabolism. In people under 50, the presence of this ring is considered an indicator of hyperlipidemia, meaning elevated cholesterol or triglycerides in the blood. It can also be one of the classic physical signs of familial hypercholesterolemia, an inherited condition that causes dangerously high cholesterol levels from a young age.
The Link to Heart Disease
The connection between corneal arcus and cardiovascular risk is real but specific. The Lipid Research Clinics Mortality Follow-up Study found that in men aged 30 to 49 who already had high cholesterol, corneal arcus was associated with a 3.7 times greater risk of dying from coronary heart disease and a 4.0 times greater risk of cardiovascular death, even after accounting for cholesterol levels, HDL cholesterol, and smoking status.
That elevated risk was concentrated in younger, hyperlipidemic men. In older adults, the association weakens considerably because so many people develop arcus regardless of their cholesterol levels. The practical takeaway: if you’re under 50 and an eye doctor spots this ring, it’s worth getting a full lipid panel to check your cholesterol. If you’re over 60, the ring alone isn’t a cause for concern.
Can It Be Reversed?
Once the lipid deposits settle into the cornea, they tend to stay. Animal studies have shown that corneal arcus can regress after the dietary cause of high cholesterol is removed, but that kind of reversal has not been demonstrated in humans, even with cholesterol-lowering treatment. The deposits don’t grow inward toward the center of the cornea, so they never interfere with the pupil or affect your ability to see.
Because the ring causes no symptoms and no vision impairment, there is no treatment for the corneal change itself. If it’s discovered in a younger person and leads to a diagnosis of high cholesterol, the treatment focus shifts to managing lipid levels to protect heart health, not to clearing the ring from the eye.
What to Expect at an Eye Exam
Your eye doctor can identify corneal arcus with a standard slit-lamp examination, the same microscope used in routine eye checkups. The diagnosis is straightforward and doesn’t require special imaging or additional testing. If you’re younger than 50, your eye doctor will likely recommend blood work to evaluate your cholesterol. If a lipid disorder is found, you may be referred to a primary care physician or cardiologist for further evaluation, particularly if there’s a family history of early heart disease or very high cholesterol.
For older adults, no follow-up is typically needed beyond noting the finding in your medical record. The absence of corneal arcus in an older person doesn’t mean anything protective either. Plenty of people with high cholesterol never develop the ring, and many with perfectly normal lipid levels do.