Sorry to hear about your SIL. Wow, I wonder if she could be experiencing an optical migraine? I've dealt with migraines for years, but to my knowledge have never had an optical migraine.

I'm currently on my fourth bout of ON but have never experienced something like your SIL, although ON seems to have different sx for different people. From what I've read, ON very rarely attacks both eyes at once. For me, it started with pain each time, first stabbing pain in the eye, then pain when moving from side to side, sort of a pulled muscle feeling. Next, the blurry spots, sort of like having grease on your contact or lens. Finally, I noticed that reds and vibrant colors were a couple of shades dimmer, sort of like wearing sunglasses. I've been told in all cases my optic nerve looked good, despite the ON.

I've had my eyes dialated countless times and have never had your SIL's experience. I think Craig's right - she most likely needs to see an MS neuro, but start with the PCP and work your way up.

Please let us know how your SIL is doing.