In Baltimore, in the USA, a group of doctors is working on a revolutionary idea, which looks like a transition from science fiction to actual science, to restore sight to the blind through electrical stimulation, which causes an artificial bypass of the nerve cells that have ceased to function. In the meantime, the surgeons were only able to bring about some short-term vision
Dr. Anat Levenstein
"Stevie Wonder wants to see", announced prominent headlines in the media channels in the United States recently and reported the great interest that the well-known singer, who has been blind since birth, shows in studies dealing with "artificial vision".
This is the revolutionary idea that is at the center of a research project at the Wilmer Eye Institute (Wilmer Institute) at the Johns Hopkins Hospital in Baltimore, Maryland in the United States. There, for several years, they have been trying to turn from science fiction to real science the idea that speaks of restoring sight to the blind through artificial bypassing of nerve cells that have stopped functioning. The main researchers leading the project are Dr. Mark Homin and Dr. Eugene Doan, and a team of researchers from all over the world works with them. The original idea of "artificial vision" is based on performing electrical stimulation, which bypasses nerve cells that have stopped functioning due to various diseases. This method is already clinically applied in medicine in other parts of the human body, such as an implant that is implanted in the inner ear and enables the rehabilitation of deaf people, for whom there is no other treatment. Similarly, in cases of blindness, which is caused by severe damage to the light-receiving cells of the retina (photoreceptors) due to various diseases - this is electrical stimulation, which bypasses these cells and enables vision.
We see with the brain. The retina is the light-receiving tissue in the eye (like elephants in a camera). It includes, as mentioned, the light-receiving cells (photoreceptors). These cells absorb the light energy, turn it into electrical energy, and transfer this electrical energy to other cells in the retina (ganglion cells). These last cells process the information partially and transmit it through the optic nerve to the brain.
That is, the role of the eye is to absorb the light energy, turn it into electrical energy, partially process the received information and transfer it to the brain, where it undergoes final processing. That is, the final result of the vision process occurs in the brain. In an extreme way, we can say that we actually "see" with the brain, and the eye's job is only to process the light energy into electrical information that the brain can understand.
In many degenerative diseases of the retina, such as retinitis pigmentosa (hereditary night blindness), and in other diseases that cause blindness, the light-receiving cells are destroyed. However, other parts of the retina (including the ganglion cells) remain normal. This is where the idea was born, that if it is possible to artificially stimulate the retina, theoretically the eye should return to seeing.
So much for the idea. Now try to examine what has already been done practically. The electrical chip To date, the results obtained on this subject in humans were in the operating room itself, during the operation, for a short period of time (duration of up to one hour).
For completely blind subjects, who do not even have a sense of light, different electrodes were inserted into the eye. The electrodes were inserted through the wall of the eyeball (in a place where it is possible to enter without damaging the eye tissues, and through which they also enter the eye in some normal retinal surgeries), and were placed on top of the retina. After that, the patient's reaction to various stimuli that were performed was tested. At a frequency of about 40 Hz they reached the sensation of light, where the stimulation threshold depended on the area where it was performed (the area of the center of vision, or the area around it).
After a correct response to simple light stimuli was achieved, i.e., people who had not seen light for years correctly identified stimulation of the retina as a light stimulus, the surgeons performed stimulations by a array of microelectrodes and came to the fact that those who had been blind for many years could, during surgery, recognize shapes such as for example Box shape, or roughly the shape of a capital letter.
It should be emphasized that to date the electrical chip, which is under development, has not yet been implanted long-term in any patient. The goal is to eventually achieve long-term responses to these electrical stimuli. That is, the next step is to implant an electrical chip on top of the retina, on which it should remain permanently. This chip sends electrical stimuli, which stimulate areas of the retina (eg ganglion cells) that are not damaged and not destroyed. Theoretically, it is possible to connect this chip to an external laser that will be mounted on external glasses and cause the chip to be activated regularly, in response to stimuli in the external environment. And this, in fact, would be "artificial vision".
It is worth noting that there are already dogs in which the chip was implanted on the retina for up to a year, without damage to the retina or the eye.
The development of "artificial vision" subsystems includes, therefore, several subsystems, each of which has its own role, and all of which are still in development stages. These sub-systems include: a camera - which will receive the images from the environment, an electronic array - which will turn the images into an electrical stimulus, a telemetry system - which will provide power and data, a system which will decode the stimuli and create the stimulus, and a system of electrodes ("the electrical chip") - which will be implanted on the retina and cause her irritation.
Stevie Wonder's interest in these studies aroused great public interest in them, especially in the United States. The original disease of the well-known singer is blindness resulting from retinopathy of prematurity, and this in the most severe form. Since he is blind from birth and has never seen light, the chances that the electric chip will help him personally are extremely small.
To this day, he has never been examined at the "Wilmar" institute, but there have been long discussions on the subject with the institute's doctors. In all these discussions, his main interest was in increasing awareness of conducting these medical studies and supporting them, and not necessarily a personal interest.
The attempt to create "artificial vision" appears, therefore, to those interested in the subject as a step in the transition from science fiction to real science. But despite the many publications on the subject, today only a certain short-term vision is possible, during the surgery itself. However, the research looks extremely promising, and there is a reasonable chance of much more serious progress over the next few years.
