Visual Snow Simulator: Patients who complain of Visual Snow literally see what resembles "television snow," that is, specs or particles that blink on and off in their vision. Unfortunately, no one knows what causes visual snow, but given its strong resemblance to "noise in the system," it could be that neural activity in the visual cortex is simply operating at too high a baseline, with many neurons firing more often than they should. At the level of perception, this would be seen as white specks in the visual field.