It seems that pornography can make you go blind, sort of. From The Economist:
“IT’S true. Pornography can make you blind. Look at a smutty picture and, according to research by Steven Most, of Yale University, and his colleagues, you will suffer from a temporary condition known as emotion-induced blindness.
Dr Most made this discovery while studying the rubbernecking effect (when people slow down to stare at a car accident). Rubbernecking represents a serious lapse of attention to the road, but he wondered if the initial reaction to such gory scenes could cause smaller lapses. The answer is, it does. What he found was that when people look at gory images—and also erotic ones—they fail to process what they see immediately afterwards. This period of blindness lasts between two-tenths and eight-tenths of a second. That is long enough for a driver transfixed by an erotic advert on a billboard to cause an accident.”