One of the many debates regarding visual prosthetics is:  where is the best location to stimulate the visual system to obtain the best result? Another concern regarding electrode implants is in regards to fixing the implant to the anatomical structure.  If the electrode moves around it will jeopardize the efficiency and might cause further damage to retinal cells.  There also arise problems with biocompatibility of the device within the retina region, regardless of position.  After a given time, the body will start to reject the implant and it is the goal of engineers to design a system that will allow long term biocompatibility.  The technology currently available also poses a problem.  The electrodes that are being tested are 4 x 4 electrode arrays (16 electrodes) but if we were to increase the array one might be able to contact more retina cells to stimulate and by stimulating more cells one might be able to transmit a more accurate representation of the surroundings.  Moreover, if an individual is born blind, it is extremely questionable if a retinal electrode implantation would benefit such individual since they will not have been “wired” to see.  If we successfully stimulate the retina, will the physiological system know what to do with the signal?