I. INTRODUCTION
Vision or visual perception is a complex sensory system of a human organism that interprets light reflected off objects onto the retina of an eye. Special receptor cells in the retina, rods and cones, convert the light intensity and color of the light into electrical signals sent to the brain via the optical nerve. Visually impaired and blind individuals have this process obstructed either physiologically or neurologically. The World Health Organization estimated in May 2009 that about 314 million people are visually impaired worldwide, and 45 million of them are blind. Although 85% can be cured through modem clinical treatment, for the other 15%, hope of a complete awareness of their surroundings lies with modem technology and innovation. They can avoid collisions through the use of a walking stick or a trained dog, but this doesn't give 3D perception. They can also feel textures using their hands, but this is time consuming. The blind tend to use the sense of touch as a substitution for vision so a proper technological solution would use this property to its advantage.