Hey, I had that about twenty years ago. The only symptom I had was that I would wake up with a headache for no apparent reason (not a migraine, but frequently nausea-inducing).

My ophthalmologist detected it during a regular examination and sent out for MRI/CAT scan/spinal tap to rule out everything else, then put me on a regimen of -- oh, now I can't remember; the medicine used for altitude sickness (diamox?) and eventually "cured" me; I haven't had a recurrence since.

I guess my point is that the grandparent poster should consider seeing an ophthalmologist and/or a neurologist at their earliest convenience. (My doctor was pleased that he'd "caught it in time"; he spoke of another patient in which it had not been detected quickly enough and that person had gone blind.)