Is 2 mm pupil size normal?

Normal pupil size ranges between 1/16 to 5/16 of an inch (2.0 to 8.0 millimeters), depending on the lighting. 3 The younger you are, the larger your pupils tend to be in normal light.

How much anisocoria is normal?

Up to 30% of the normal population has anisocoria. The amount of anisocoria can vary from day-to-day and can even switch eyes. Anisocoria that is NOT associated with or due to an underlying medical condition is called physiologic anisocoria.

What is considered significant anisocoria?

Physiological Anisocoria Physiologic anisocoria is usually defined as a pupillary inequality of 0.4 mm, seldom greater than 0.8 mm, not due to a secondary cause. If the anisocoria is physiologic, the difference in pupil sizes should remain equal in dim and bright lights.

Can anisocoria be permanent?

Physiological anisocoria may be temporary or permanent, depending on individual cases. About 15–30% of the population experiences physiological anisocoria. The difference between the pupil sizes is more or less constant, even when the light changes, and is not usually of concern.

What is a normal pupil size in mm?

The normal pupil size in adults varies from 2 to 4 mm in diameter in bright light to 4 to 8 mm in the dark. The pupils are generally equal in size. They constrict to direct illumination (direct response) and to illumination of the opposite eye (consensual response). The pupil dilates in the dark.

Why are my baby pupils different sizes?

Most often, the diameter difference is less than 0.5 mm, but it can be up to 1 mm. Babies born with different sized pupils may not have any underlying disorder. If other family members also have similar pupils, then the pupil size difference could be genetic and is nothing to worry about.

Should the criteria for anisocoria be increased?

When the criterion for anisocoria was shifted to ≥0.2 mm or ≥0.6 mm, the prevalence of anisocoria shifted significantly. Using a higher cutoff of ≥0.6 mm effectively reduced the number of healthy individuals who exhibit anisocoria in every light setting to almost zero.

What can old photographs tell us about anisocoria?

Old photographs may provide information since symptoms may not exist or may go unnoticed. Chronic anisocoria without associated symptoms may point to a benign process such as physiologic anisocoria, whereas sudden-onset anisocoria in the setting of other symptoms may be more worrisome.

What is an example of physiologic anisocoria?

Physiologic anisocoria may be intermittent, persistent, or even self-resolving. Congenital anomalies in the structure of the iris may contribute to abnormal pupillary sizes and shapes that present in childhood. Examples include aniridia, coloboma, and ectopic pupil.

Which ophthalmic history findings are characteristic of pharmacologic anisocoria?

Complete ophthalmic history is important as coexisting ocular conditions, previous surgeries or trauma to the head or orbit may contribute to anisocoria. A thorough review of medications, especially topical eye drops, may provide explanations for pharmacologic anisocoria.