When Pupils in the Eye Don’t Work Properly

What happens when pupils in the eye don’t work properly?

The pupil is the opening in the center of the iris (the colored part of the eye) that allows light to enter the eye and thus begins the process of sight.

However, there are a number of eye conditions that can affect the function of the pupils. In this post, we’re going to describe two — Adie’s Pupil and Horner’s Syndrome.

Adie’s Pupil

Adie’s Pupil is a neurological disorder than impedes the pupil’s ability to constrict as it should in the presence of bright light. Symptoms include:

• having a pupil that is larger than the other
• a pupil that doesn’t get smaller in bright light
• light sensitivity
• blurry vision
• problems with near vision

Horner’s Syndrome

In contrast to Adie’s Pupil, people with Horner’s Syndrome (a rare disorder with a number of associated conditions) have a pupil that is persistently small with little or delayed opening (dilation) of the affected pupil in dim light.

Diagnosing Pupil Disorders

One method Ophthalmologists employ to diagnose these disorders in conjunction with other tests is to do Pupil Response Testing.

To check for Adie’s Pupil, an Ophthalmologist will expose the patient to bright light. As you might guess, the pupil will fail to constrict properly.

Conversely, the pupil of a person with Horner’s Syndrome will generally fail to dilate when observed in a dark room. Both of these conditions require medical evaluation.