A comparison of text reading speed using square and rectangular arrays for visual prosthesis

With the increase of the number of the blind, demand for visual prosthesis is increasing. Text reading is one of the most important visual functions to the blind. Therefore human trials and simulations of prosthetic vision have already been carried out for testing an improved system or studying rehabilitation of people who implant prosthesis. But although forms of electrode arrays used in those studies were various, differences between performances of them were not considered for the text reading. Therefore we tested reading performances among three different array shapes (square (32×32), vertical(42×22) and horizontal(22×42) shape array) by blind simulation experiment with head mount display device. As a result, horizontal array showed the best performance when window length for horizontal array was 3. However, when the window width for horizontal array increased to 3.5, performances between horizontal array and square array were similar. In the experiment of lower resolution (8×8) and window width, square array showed the best performance than other arrays.