The Forehead Retina System (FRS) uses a special headband to selectively stimulate different mechanoreceptors in forehead skin to allow visually impaired people to "see" a picture of what lies in front of them. The Forehead Retina System is the result of collaborative research by Tachi laboratory at the University of Tokyo and EyePlusPlus, Inc.

The Forehead Retina System uses tactile sensations in the forehead to present a "picture" of the outline of objects; this enables visually impaired people to "see" what is in front of them.

Yes, you could have eyes in the back if your head. Bald men could have 360 degree vision. There might be military uses for this.

LiveScience.com - Vision Gear Bypasses the Eye