I spent a weekend with the sunglasses, (it was cloudy, but who cares, us Brits love to wear our shades sans soleil). The facility that enables the wearer to "see behind" involves a mirrored coating on the inside of each lens, so to actually utilise the remarkable properties involves moving your head at strange angles. Needless to say, while in my local supermarket I not only looked odd wearing shades, I also looked like I had a particularly bad crick in my neck. I did see some fantastic things I would otherwise have missed out on - a five-year-old picking his nose, and an older lady feeding her poodle chocolate. The glasses can have some truly funny and enlightening uses - at fashion shows, for example. You want to see what the person behind you is wearing/doing without making it obvious - or you're so busy watching the crowd you watch the show using the glasses. The possibilities are endless, especially if you are an aspiring 007.
British standard UV protection see-behind-you sunglasses, pounds 15 from Spycatcher, 25g Lowndes Street, SW1; for mail order inquiries, 0171-245 9445.