What are Floating white spots in vision after blowing nose?

Answer 1

Blowing the nose increases blood pressure inside the head and eyes. The spots where the arterioles are dilated in front of the retina elicits direct stimulation of the photoreceptor cells which line the retina, causing the eye to send signals to the brain. So these white spots, which are technically called flashes are the interpretation that the brain makes of this signal. Flashes are common, and may increase in some conditions, such as migraine. If they increase in intensity and persistence, they may be abnormal, possibly indicating a tear in the retina. Answer by Renato M.E. Sabbatini, PhD, Brazilian neurophysiologist and science writer. http://www.sabbatini.com/renato