From an article on live www.science.com.
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.
The gear combines to present an outline of what’s in front of the viewer.
Here’s how it works:
A miniature camera mounted on a pair of sunglasses takes a picture of the scene in front of the user.
The digital picture is processed and converted into tactile information with two processes. The first uses a special algorithm to extract the spatial outline of the main contents of the visual field; edges are enhanced. The second process is a temporal band-pass filter to enhance time-varying information.
Finally, the processed visual image is converted to tactile sensations by electrical stimuli; the electrodes in the special headband selectively stimulate the different mechanoreceptors in the forehead skin.
FRS uses a Tactile Primary Color Approach; by separately stimulating three different types of mechanoreceptors in the forehead skin – Merkel cells, Meissner corpuscles and Pacinian corpuscles – the device can approximate an RGB (Red-Green-Blue) color system. FRS thereby approximates color visual construction.
FRS is not yet available as a product; prototype units have been built, and are being demonstrated at conferences and schools for the blind around the world.