Nike is developing a pair of glasses for bike riding that could very well save your life. The glasses will extend your peripheral vision so that you are able to see objects behind you. The Nike Hindsight glasses have a special lens on the sides that allows for a field of view greater than the human limit of 180º. It will give you an extra 25º of viewing on both sides, making you see things like some bugs no doubt see the world.
The lenses distort the images on the side but the human eye can only detect motion in that area anyway, so the image will remain clear to you. You’ll be able to see cars or pedestrians coming up from behind you. It’s still a concept at the moment, but I’m sure this is one we will actually see in about 5 years or so.