Anisocoria is when your eye’s pupils are not the same size. The pupil allows light to enter the eye so that you can see.
Anyone can have pupils that differ in size with no problems. In fact, one out of five people have pupils that are normally different sizes.
Sometimes, though, having uneven pupil size can be a symptom of a serious eye problem. People who may get anisocoria include those who have:
Often people don’t realize their pupils are different sizes. Some people only notice it when comparing old and recent photos of themselves.
However, if anisocoria develops from an eye health problem, you may notice other symptoms related to that problem. These symptoms may include:
If you experience any of these symptoms with anisocoria, call an ophthalmologist right away.
To diagnose anisocoria, your ophthalmologist will examine your pupils in both a lighted room and a dark room. This allows them to see how your pupils respond to light. This can help them figure out which pupil is abnormal.
Your ophthalmologist will also check your eyes with a slit-lamp microscope. This instrument lets your eye doctor look at your eye in small, detailed sections. That makes it easier to spot problems.
If you have other symptoms along with different pupil size, your ophthalmologist will do other tests to learn more about your condition.
Usually anisocoria does not need to be treated since it does not affect eyesight or eye health.
If anisocoria is related to an eye health problem, that problem will need to be treated.
If you have questions about anisocoria, be sure to ask your eye doctor. Your ophthalmologist is committed to protecting your sight.