Horner's Syndrome
Horner’s syndrome is a pattern of eye and facial changes caused by reduced “sympathetic” nerve signals to one side of the face. It isn’t a disease by itself—it’s a clue that something along that nerve pathway has been affected, so clinicians focus on finding the underlying cause. Q: What is Horner’s syndrome? A: A condition where the nerves that help control the eyelid, pupil size, and sweating don’t work normally on one side of the face. Q: What are the usual signs? A: A droopy upper eyelid (ptosis), a smaller pupil on that side (miosis), and sometimes less sweating on that side of the face (anhidrosis). Some people also notice the affected eye looks “less open.” Q: Does it hurt or affect vision? A: Horner’s syndrome itself doesn’t usually damage the eye or directly cause vision loss, but the pupil difference can be more noticeable in dim light and may be associated with other symptoms depending on the cause. Q: What causes it? A: Anything that disrupts the nerve pathway from the brai...