Which one was first?
Asking who made “the first bionic eye” has several possible answers, depending on the definition. If it means the first time electricity made a blind person see light, the answer is in the eighteenth century. If it means the first implant on the brain’s surface, it is a volunteer in London in 1968. If it means the first retinal prosthesis used in people, it is the early 2000s. And if it means the first system that regulators approved for sale, it is around 2011 to 2013. These are different milestones, and none is the only correct answer.
Flashes of light in the 1750s
The earliest account usually cited comes from the French physician and scientist Charles Le Roy, who in about 1755 reported passing an electric discharge through a blind man’s head, from a device storing static electricity. The man, whose blindness came from a cataract, saw flashes of light. The report is brief and its exact details are hard to verify, but it is cited as the first sign that stimulating the visual system electrically could produce visual sensations in a blind person.
The sensations are now called phosphenes: spots or flashes of light that appear without light entering the eye. They are the raw material of every visual prosthesis, since a device must create patterns of them.
Foerster and the cortex
In the 1920s, the German neurologist Otfrid Foerster stimulated the surface of the occipital lobe, the brain’s visual area, in patients who were undergoing surgery with local anesthesia. They reported seeing small spots of light, and he found that the position of the spot depended on where he stimulated. Later neurosurgeons, including Wilder Penfield, confirmed and extended these maps in the following decades.
This gave a map of the visual cortex in which different points correspond to different locations in the visual field. If the map was regular, the argument went, a grid of electrodes could in principle draw a picture.
London, 1968
The step from brief tests during surgery to an implanted device was made by Giles Brindley and Walpole Lewin. In 1968 they reported implanting an array of electrodes over the visual cortex of a blind woman, with a radio receiver placed under the scalp. When individual electrodes were stimulated through the skin, she saw phosphenes at specific places in her visual field. She could tell where on the array each spot would appear, and the researchers could produce simple patterns.
This is a strong candidate for the first true visual prosthesis, in that it was an implanted system that a blind person used to perceive controlled patterns of light. It was a research device, with many limits: the array could be used only at a lab, the number of phosphenes was small, and the spots did not form a clear picture.
The 1970s and the cortical systems
Following the London work, William Dobelle, working in the United States, developed cortical stimulators and tested them on blind volunteers from the 1970s. Some of the systems included a head-mounted camera and a computer that converted images into stimulation patterns, so that a volunteer could use an early form of artificial vision outside the lab. Dobelle’s later work continued into the early 2000s and generated both attention and controversy, partly because of how the work was reported and the commercial aspects of it. Participants’ benefits were modest, and the approach was not widely adopted.
Cortical implants had advantages, as they might work for many causes of blindness, but they brought the risks of brain surgery, including infection and seizures. They also depended on electrodes lying on the brain’s surface, where the spread of current limited resolution. Interest in them was renewed in the 2010s with more advanced electrodes, and work on brain-computer interfaces and implanted electrodes in the cortex continues.
The retina becomes the target
From the 1980s and 1990s, attention moved to the retina, helped by the observation that in diseases such as retinitis pigmentosa the later layers of the retina remain partly intact. Groups in the United States and Germany developed designs that placed electrodes on or under the retina. Silicon chips, with advances in microfabrication, made small arrays possible. Some of the first human tests were short experiments in which a surgeon placed a temporary electrode on the retina during surgery, and the patient reported light spots.
From around 2000, chips were implanted in volunteers for longer periods. In 2002, a 16-electrode epiretinal device was first implanted in a patient in the United States. That device was followed by a 60-electrode version, whose clinical trial began in the late 2000s.
Approvals
The step that most clearly separates a research device from a product is regulatory approval. In 2011, the 60-electrode epiretinal system was granted a CE mark for use in Europe, and in 2013 it won approval in the United States for adults with advanced retinitis pigmentosa, under a pathway meant for devices that serve few patients. In 2013, a German subretinal chip with around 1,500 light-sensing elements also received a CE mark. These are the best candidates for the first approved bionic eyes, and details of the dates differ slightly between sources.
Approval does not mean normal vision. It meant that regulators judged that the benefits for a very specific group of patients outweighed the risks, using tests such as finding a light or following a line.
A cautious summary
The “first bionic eye” is the end of a chain: Le Roy’s flashes, Foerster’s maps, Brindley’s volunteer, Dobelle’s portable system, the early retinal chips and the approved devices. This account concerns who did what first, with the caveat that some early records are incomplete and some dates are approximate. The word “marvel” in the title fits the science. Any claim of restored sight should be read with care.