I have seen it, and it does work. Why? Here's one theory... there may be others... An important point is it works like magic! What a boon in recurring monsoon problem? Refraction takes place when a clear or opaque object, such as a piece of glass or a bag of water, alters the course and velocity of light. The rays of light, which normally travel in a straight line, bend. This effect is responsible for a number of optical illusions. In theory, refraction can be just as confusing for some species of insect , especially the housefly . It boasts a highly sensitive array of eyes which allow it to see in multiple directions at once. The insect's head mostly consists of a pair of large complex eyes , each of which is composed of 3,000 to 6,000 simple eyes . These eyes can't move or focus on objects like human eyes, but they provide the fly with a mosaic view of the world around them. Each simple eye provides one small piece of the puzzle, much l...