I'm going to have to be very careful about the words I choose to describe the following story. Very careful indeed.

Remember the age-old warning - usually given by your mother - that, er, indulging in rather too much of a certain private activity (oh, don't make me say it, you know what I'm talking about) can make you go blind? Well, it could well be true, as psychologists in the US have discovered. Looking at, um, saucy images - as well as gory ones, interestingly - can induce temporary emotion-induced blindness, albeit for only one-fifth of a second.

So if you're visually impaired and are fed up with the oh-so-funny comments from that bloke in the pub about what you got up to when you were a kid that made you lose your sight, you've now got an answer that should make him shut up once and for all. Just tell him you've got long-term emotion-induced blindness. Or maybe not, eh?