I do not have any information whether anyone among the eye prosthetics technicians has been engaged in electronic vision or producing devices assisting way finding for the blind people, however this elaboration has been carried out for several decades already. Numerous options and device models have been suggested however no special progress has been made.  The public recognition of the failure of all these efforts is demonstrated by the fact that in these latter days there has been a growing interest focused not on the means to facilitate adaptation of the blind people to the general environment, but on the devices that adapt some of the environment to the needs of blind people. Such devices could include, for example, audible traffic signals. In disregard of the great importance of these efforts, it is presently required to recognize them as of little promise ones in the future, because the blinds still remain placed in a particular ghetto.

Currently, there are no unconquerable difficulties in receiving and processing the information relating to situation in the living environment or in the street. There exist very sophisticated programs for the computer analysis of video images or signals from ultrasonic radars. The means of communication of this information to a blind user is at present an unsolved problem. The information transmission method through audio signals, which has been in use until recently, is hardly suitable because it interferes with the analysis and assessment of ambient sounds from the environment. Attempts were executed to communicate visual information by using tactile sensitivity of a skin or mucous tunic of a mouth. Efforts are being made even to implant electrodes in the cerebral cortex.

We have executed an attempt to use an eye prosthesis to transmit information regarding the environment to the patients without both eyes or with an absolute blindness The method is based on the effect of weak electrical impulses leaving the prosthesis on the mucosa of the orbital cavity and controlling the device by recording the movement of the eye prosthesis .

A few well-known facts serve as theoretical underpinning for such opportunity.

In the first place, even if both eyes are completely removed, some portion of the organ that is usually defined as a visual analyzer retains. Availability of dreams with visual images and the oculomotor muscles activity, which can be demonstrated by movement of completely blind eyes or eye prostheses, notably, with movement to the “appropriate” side, are the most familiar signs of this effect. This phenomenon is well known and is being used both by us, the eye prosthetics technicians, and the experts in the sphere of physical disability. The old technique of debunking the blindness simulation was the request to look in the voice direction - a blind person turns eyes in the voice direction, when a simulator looks straight.

In the second place - the mucous membrane covering a stump of the removed eye and an orbital cavity is in a certain degree innervated and is capable to perceive the impact of weak electrical impulses, if not over its whole area, then in separate sectors. We investigated the sensitivity of conjunctiva to electrical impulses. On a healthy eye it makes 80 - 100 μA. There is a large difference in results ranging from 100 to 300 μA, among the people with an eye prosthesis, and it makes from 100 to 300 μA and perhaps more because we did not explore sensitivity at high current values.

In the third place - the role of eye movements in the vision process is long ago and well-studied. And although the exact way of maintaining of the relationship between the niduses of three pairs of oculomotor nerves and other brain regions performing the act of vision is unknown, however the very existence of such a link is undeniable. It should be noted that the nuclei of the oculomotor nerves are in the upper tubercles of the quadruple, where the first neurons of the optic path end and from where the transmission of visual information to the cerebral cortex passes. It was demonstrated a long time ago that if an absolutely healthy eye with normal vision is artificially immobilized, it becomes blind, and its eyesight is not restored until resuming of the possibility of its movement. The nature of motion of eyes when looking at subjects has been studied and may be applied in the creation of assistance devices for the blind people.

For the fourth place, it has been established long ago and it has long been officially recognized that a person can deal without outside assistance if his vision acuity makes more than 3 per cent and the viewing field is more than 10 degrees in diameter. These two figures can be considered an interim target for the electronic devices being elaborated

We propose the device which will assist the blind people that is operational already now, and we believe that it has great potential for perfection. There ported  device includes two units and a portable computer.

A video camera, a reader, an antenna are installed in one of the units. All components can be installed on a spectacle frame or sunglasses. Connection with a computer and a power supply source for a computer is executed via standard cables. Information from a video camera is sent to a computer where it is processed and transmitted to a reader, which is connected with the second unit via antenna. Connection between units is accomplished in two directions through the wireless communication protocol  NFC. An example of such communication in other areas is the use of contactless payment cards.

The second unit is placed inside an eye prosthesis. The modern microelectronic elements base permits to install into an eye prosthesis a microchip, an accelerometer (this part allows for the recording of acceleration, in such a way fixing the acceleration projection of eye prosthesis), the NFC antenna and a power supply source which will enable the transmission of information by impacting a conjunctiva with electrical impulses with such a strength which will be perceived by a patient.

The applicable chip has 8 active output terminals. A part of the output terminals are used for the electrodes that pass to the rear surface of a prosthesis.

The device operating principle

At the initial stage, we restrain ourselves only with analyzing the background brightness and the separate environmental fields. The video camera has a field of vision of 80 - 120 degrees of which only the area of 10 degrees is active at any specific time and this area is in constant motion.

 If an object that is significantly different in brightness from the background in one or the other side occurs (darker or lighter than the background), a short-term electrical pulse is transmitted via electrodes to a definite portion of the mucosa under a prosthesis. This impulse is quite clearly perceived by a user as a weak injection and allows a user to determine from which direction a light or a shadow emerged. In case a user moves the visual axis of a video camera towards that object, the repulse will be transferred to a prosthesis center. 

An optional example - a blind person is placed into a room with a bright window and a door opened to a dark corridor. When both a light window and a dark door get into the active area of the field of view of the device, a person will perceive the pulse and will shift the device gaze in its direction.

Preliminary results

In the process of our internal benchmark tests it has been proved that the opportunity of using a prosthesis in order to distinguish the direction of a hand movement from a face (from the right to the left or from the top to the bottom), and, unfortunately, we have had to stop since for further study, a complete cycle of other tests proving the safety of the device should be conducted. The device and its documentation are currently transmitted to our Ministry of Health for approval of the testing sequence.

Notwithstanding a pause in the tests, I have no doubt as to the working efficiency and effectiveness of this device due to its feasibility, since it is relatively cheap and does not require the conduct of surgical operations. Furthermore, it is easily perceived by users as just a kind of eye prosthesis, to which they have been already accustomed and have a long history of using of which. If desired, they can easily refuse from it.  Preliminary calculations demonstrate that with a satisfactory state of innervation of the mucous membrane at the orbital cavity with a field of view of 10 degrees, it is possible to achieve the resolution of the device up to 1/20-30 angular minutes, which complies with the visual acuity of about two to three percent. The possibility of its assembly from production-run parts in the conditions of a conventional laboratory of eye prosthetics is an important advantage of the device.

At present, the development of devices in the general completion but for its testing and launch into production requires participation in cooperation with what we are looking for partners to complete this project.

It seems that the problem of rendering assistance to completely blind people in the near future will be addressed not in neurosurgery clinics which implant electrodes or chips in a human brain, but basically by our colleagues in eye prosthetics centers.

Thank you.