Santa Clara, CA
A 56-year-old female asked:
One of my pupils is dilated to almost twice the size of the other. what can cause this?
2 doctor answers • 3 doctors weighed in

Dr. David Dunnanswered
Phlebology 43 years experience
Anisocoria: Anisocoria refers to unequal pupils.
Physiologic anisocoria is very common and normal in up to 20% of people. The variation should be no more than 1mm and both eyes should react normally to light.
It can be dangerous if it is a form of horner's syndrome (e.g. Carotid dissection) or from damage to the third nerve (e.g. Aneurysmal expansion) so you should get it checked out!
Created for people with ongoing healthcare needs but benefits everyone.
5.1k viewsReviewed >2 years ago

Dr. Robert Uyedaanswered
General Surgery 47 years experience
Unless you went to: Eye doctor and he administered eye drops to dilate your pupils, this is a dangerous sign of brain damage. Get to emergency dept of your nearest hospital right away.
Created for people with ongoing healthcare needs but benefits everyone.
5.1k viewsAnswered >2 years ago
Last updated May 7, 2018
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