The size of your pupil can tell your healthcare provider quite a bit about your health.
It’s an important key to unlocking possible medical conditions you might not otherwise know about.
There are manyparts of the eye, and the pupil is among the most important.
Verywell
It controls the amount of light that enters your eye.
It also continually changes size.
Your pupil naturally widens and narrows based on the brightness of the light around you.
It also changes size depending on whether you are looking at near or far objects.
What Is the Pupil?
The pupil is the round, black circle in the center of theiris.
Your iris is the colored part of your eye.
Your pupils are similar to a camera aperture.
They widen or narrow to let more or less light in.
Pupils can expand to become larger (dilate) orcontract to become smaller(constrict).
Dilated pupilscalledmydriasisrange from 4 to 8 millimeters in size.
Your pupils also constrict slightly to look at close objects and dilate slightly to look far away.
The younger you are, the larger your pupils tend to be in normal light.
Although it is rare, some people can have naturally larger pupils.
People with naturally large pupils are prone to light sensitivity.
The larger pupil allows more light in the eye, which can be uncomfortable but not harmful.
They may also test your pupils' response to objects that are nearby, such as small print.
Any differences between your pupils are also noted.
The optic nerve andoculomotornervesboth control pupil size.
These nerves receive some of their messages from the autonomic nervous system.
This part of the nervous system controls all of your vital functions, many of which are automatic.
A disruption of the autonomic nervous system might cause changes in how your pupils react to stimuli.
That’s why the size of your pupils can indicate health conditions completely unrelated to your eyes.
Associated Conditions
Pupil size abnormalities can sometimes mean you have a disease or health condition.
This is just a small sample of medical conditions you could have.
There are also other conditions that can cause irregular pupil function.
Eye specialists may use a gadget called an infrared pupillometer to measure the size of the pupils.
This would interfere with the clear vision you are hoping for from the surgery.
For this reason, measuring pupil size is an important step in deciding if LASIK is right for you.
Summary
The size of your pupils can give your healthcare provider clues about your health.
Pupil size constantly changes according to the amount of light entering it.
It also changes depending on whether the objects you are looking at are near or far away.
That’s because people with naturally large pupils may experience glares and halos following a LASIK procedure.
In: Walker HK, Hall WD, Hurst JW, editors.
Clinical Methods: The History, Physical, and Laboratory Examinations.
Boston: Butterworths; 1990.
American Academy of Ophthalmology.Why are my pupils so naturally large?
LaRoche MJ.Anisocoria and an array of neurologic symptoms in an adult with Ewing sarcoma.J Adv Pract Oncol.
McDougal DH, Gamlin PD.Autonomic control of the eye.Compr Physiol.
2015;5(1):439473. doi:10.1002/cphy.c140014
Johns Hopkins Medicine.Pupillary disorders including anisocoria.
American Academy of Ophthalmology.4 neuro conditions not to be missed.
March 23, 2016.
Brigham And Women’s Hospital.What is a brain aneurysm?
2003;110(8):1606-14.
Doran M, Karmel M, Stuart A.4 neuro conditions not to be missed.
American Academy of Ophthalmology.
