I don't know whether this is in the same category, but my granddaughter, age 13, has had problems with "flashing" eyesight. She recently saw a strobe light and said that's how she sees. She has blackness rather than snow. She has also described an experience where her field of vision is covered with overlapping black circles (light spaces in-between), and a "sparkling" effect in the black areas. This happens only once every several months. Her flashing started about 2 years ago and was intermittent. She went through this last summer without the flashing, but it started up about three weeks ago and is now 24/7. She's been to a number of doctors, even a neurologist at MD Andersen, but no diagnosis. Migraine headaches was suggested and she was put on medication, which caused severe forgetfulness, so she came off of that. I will check out the UCSF research, but can empathize with your frustration in getting help for your daughter. My granddaughter's school won't provide any help for her until she is classified IEP, which requires a diagnosis. Her parents are working on getting her help under a 504 classification. Like you, I would appreciate hearing from anyone who may have any experience with this.