As you age, the structure and appearance of your body change. This is natural and not typically a cause for concern. As your skin, bone structure, and hair color change due to aging, your eyes may change, too.

It’s not unusual for blue-tinted rings to appear around your iris — the colored part of your eye. This condition is called corneal arcus.

There may be a link between early onset corneal arcus (also called arcus senilis) and cardiovascular disease. Keep reading to find out what causes corneal arcus and when it’s a cause for concern.

Blue rings around the iris are caused by cholesterol deposits in the eye. The deposits are actually white or yellowish but can appear blue.

This might sound dangerous, but it isn’t. Researchers estimate that this condition impacts anywhere between 20 and 35 percent of people, becoming increasingly likely as you age. By the time you reach age 80, your chances of developing corneal arcus are nearly 100 percent.

For those under age 40, the condition is rare and may be a cause for concern

Corneal arcus is considered rare in people under age 40. If you notice blue rings around your eyes forming in your 30s or before, you could be at a greater risk of developing heart disease.

Talk to a doctor if you’re under 40 years old and notice symptoms of corneal arcus.

Corneal arcus is often identified by a blue ring surrounding your iris. The rings can also look gray, white, or yellowish.

When you observe your eye, it may appear that corneal arcus rings are right next to your irises. The cholesterol deposits that cause corneal arcus rings to form are actually located in your cornea, the outer layer of your eye.

If you notice a whitish looking film or a pale cast over your whole eye, that isn’t a typical sign of corneal arcus. A white cast over your eye can be a symptom of cataracts and will need to be diagnosed by your eye doctor.

Blue rings around your irises are a common condition for older people. If you’re over the age of 60 and notice these types of rings starting to take form, corneal arcus may be part of your natural aging process.

If you’re 40 or younger and have corneal arcus symptoms, you may be at greater risk of developing heart disease.

A 2015 study of 227 participants showed that corneal arcus is associated with a higher risk of cardiovascular disease in patients with familial hypercholesterolemia. Talk to a doctor if you’re under age 40 and notice symptoms of corneal arcus.

Corneal arcus is considered a benign condition. That means it isn’t harmful to your health and no treatment is typically required.

As with any eye or eyesight condition, it’s recommended that you make an appointment with your eye doctor for a complete eye check and vision exam as soon as you notice a change in the way your eyes look or behave.

A doctor can rule out any additional concerns, and make sure that your eyes are still in good health.

Corneal arcus has similarities to another eye condition called limbus sign.

Limbus sign is caused by calcium deposits in your cornea. This condition causes a milky white film to appear over your eyes and may change the way your eye coloring appears.

Limbus sign doesn’t appear as rings around your iris. It causes a yellow or off-white color to appear in your cornea. Limbus sign is not a benign condition and may require treatment.

Corneal arcus is a natural part of aging for many people. Noticing blue eyes rings around your iris is not usually a reason for concern.

Make sure to get your eyes checked by your eye doctor regularly to make sure that your eyes are healthy.