The pupil is the opening in the center of the iris which is colored part of the eye. Light passes through the pupil to reach the retina in the back of the eye. Pupils become larger in the dark (dilate) and smaller in bright light (constrict). When you come in for a complete eye examination, we pay close attention to your pupils. The reason is that they tell us a lot about how your eyes and even your brain are functioning.
The nerves that control you pupils travel a long way. They start in the eye detecting brightness, go back into the brain, down to the spinal cord, back over your lungs and again back into eye to control the small muscles in the iris. Any problem in the eye or anywhere along that pathway (such as a tumor, stroke or head trauma) can affect how your pupils function. How do we check your pupils? We take a small light and swing it from one eye to the other. We then record the size, shape and how quickly each pupil responds to light.
Up to 20% of people have pupils that are not the same size so this is generally not of concern. However, a new change in your pupils is different story especially if it is associated with of the following: a recent head injury, blurred vision in one eye or a new drooping eyelid. If any of these situations apply, you should come in right away for a thorough eye examination.
The evaluation of the pupils is just one of the many components of a complete eye examination which is a thorough medical evaluation of your eyes and how your brain processes visual information. See you soon!
Dr. Josephine-Liezl Cueto is a board certified ophthalmologist (Eye Physician and Surgeon) specializing in medical and surgical eye care. For more eye care information, call 262-241-1919 or visit www.LakeShoreVision.com.