My 15 year old daughter has been having "episodes" of dilated pupils, lasting hours at a time, and short episodes of blurry vision, lasting only a few minutes, and also short episodes of very sharp head pain, again, lasting only a few minutes. She does not use drugs at all, and she is very active in Color Guard - so may get hit in the head occasionally - but denies a recent injury. She saw an eye doctor, all checked out ok, they said no swelling of the optic nerve.