Pupils that don't dilate

What does it mean if your pupils won't dilate? My son is 2000 miles away and in the ER beause he can't see out of his right eye. He's been having headaches and numbness in his right hand. They're going to do an MRI and I told him to tell them that he needs an EMG since I have Muscular Dystrophy. He's 39 years old. Does this sound like something familiar?

[John C Hagan III, MD, FACS, FAAO]

Your sons symptoms are serious things and require a full work up to be sure he doesn't have tumor, MS, aneurysm.

JCH MD