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Eye and Vision Care

Right Eye Dilated But Not the Left



my right pupil is dilated and my left one is not...about 5 days ago i went to the Emergency Room with this and all they did was tell me it was a condition with a headache.. they did a CT Scan and everything but they did not find anything. they dilation had gone down until today it is the same way it was the other day. i have no headache or anything . honestly, i feel fine. the only thing that is irritating me is that my eye is messing with my vision. its a little blurry and fuzzy. please can you try and help me with this?


I can't be sure without examining you, but what you have described is a well-documented but poorly-understood eye condition called Aide's tonic pupil. It is more common in women than in men, and is usually harmless. Some possible causes are viral infections, systemic neuropathies, and trauma - but most are idiopathic (no definite cause found).

If it is still present, you should see your eye doctor. He or she can observe micro-spasms around the pupil during a slit lamp examination and can also instill a weak concentration of a pupil-constricting drug to make sure the anatomy, neurology, and physiology in the affected eye are all normal.

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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