Home HealthTopics Health Centers Reference Library Research
Join us on Facebook Join us on Facebook Share on Facebook

Eye and Vision Care

One Pupil Dilated



First of all, I have gone to two opthamologists. My vision has been blurry on and off for almost a month now, but mainly from one eye. I went to the opthamologist a week ago and she said she couldn`t find anything wrong and that my vision was slightly worse in that eye than the other, but no big problems. Then a couple days ago I noticed my left eye was about 4x the size as my right eye, almost took up my whole iris. It went down slightly over the night and I headed to another opthamologist the next day.

He couldn`t find any issues with my eyes, so said it could be Adie`s Syndrome, a chemical that I got in my eye, or Diabetes. I don`t think I have an other symptoms for Adie`s except excessive sweating, I am not sure a chemical in my eye would have caused the blurryness over the last month and Diabetes (I am going to try to get tested this week), I eat very well, exercise 5-6x per week...overall great health.

Any other ideas what this could be? I woke up this morning and the left high is still slightly larger than the other, but I am not seeing nearly as bad blurriness through the eye as before.


Adie's tonic pupil is a poorly-understood eye condition in which the pupil's reaction to light - both direct and indirect - is almost abolished. It usually occurs in one eye only, with the affected pupil being larger than the other one and also having reduced focusing ability at near. It usually occurs in females between the ages of 20-40; and is a benign and self-limiting condition probably caused by a low-grade viral infection.

Adie's pupils are hypersensitive to weak concentrations of eye drops that constrict the pupil, so this test should be performed by your ophthalmologist or optometrist to confirm the diagnosis.

If that test does not confirm the diagnosis, then you should see a neuro-ophthalmologist who will probably order an MRI to find the cause of your symptoms.

For more information:

Go to the Eye and Vision Care health topic, where you can:

Response by:

Robert D Newcomb, OD, MPH, FAAO Robert D Newcomb, OD, MPH, FAAO
Professor Emeritus of Clinical Optometry
College of Optometry
The Ohio State University