The idea of enhanced vision through electronic means, present in works of science fiction such as Star Trek and Neuromancer, is gradually becoming a reality in modern medicine. Researchers have been developing bionic eyes capable of recovering some lost vision, although current functionalities are still elementary and constantly evolving.
In the future, these devices may go beyond the limits of natural human vision, enabling image manipulations impossible for the biological eye or allowing the perception of light outside the visible spectrum.
To date, implants have been aimed at combating retinal failures, the light-sensitive layer located at the back of the eye, which is essential for perceiving the world. When the retina suffers severe damage, the consequence can be total blindness.
Efforts to treat retinal blindness with implants began more than twenty years ago. One of the first devices, created by the German manufacturer Retina Implant AG, used a light-sensitive chip positioned under the damaged retina. This chip communicated with the remaining healthy retinal cells, which in turn sent the visual signal to the occipital cortex, the brain area responsible for vision.
The surgery required to install this chip lasted about eight hours, involving the creation of a cranial recess behind the ear to insert a power receiver and subsequently connect it to the chip via a wire under the skin. However, the device provided only rudimentary vision, manifested as flashes of light resembling the shape of the observed object. Furthermore, many implants failed over time, possibly due to rapid eye movement or corrosion caused by internal saline fluid. Retina Implant AG ceased operations in 2019, citing the lack of medical advancements as a determining factor.
Another innovative device, the Argus II, combined a camera attached to glasses with a chip surgically implanted over the retina. The image captured by the camera was converted into a signal and transmitted wirelessly to the chip (along with power), which stimulated the healthy cells of the damaged retina using an array of 60 electrodes. Despite initial promising results and FDA approval in 2013, the ARGUS II also did not demonstrate sufficient efficacy and was discontinued in 2019.
Despite these setbacks, research into creating artificial vision has continued. A more recent methodology involves using an external camera that transmits energy and image data wirelessly to a chip inserted into the occipital cortex. This technique is based on studies that applied electrical probes directly to the occipital cortex to stimulate visual perception. This approach can benefit patients with retinal diseases or those affecting the optic nerve, which connects the retina to the brain, although the exact resolution achievable remains uncertain due to the loss of high retinal resolution and complex signal processing.
ReVision Implant, based in Belgium, is testing this technique and plans to start its first human clinical trial in October 2026.
Another alternative is the use of glasses that transmit images and energy to a sub-retinal chip, inserted surgically via infrared signal. The Prima device, which employs this technology, was evaluated in a specific condition of the retina known as dry age-related macular degeneration (AMD), one of the main causes of blindness. In a small clinical study, the Prima managed to restore functional central vision in 81% of participants, allowing them to read letters, numbers, and words. Currently, this device already has authorization for use in thirty European countries.
Because AMD is much more prevalent than hereditary retinal diseases treated by the previous systems, the Prima attracts more investor interest. However, there are important ethical considerations. Unlike patients with hereditary diseases, most affected by AMD maintain good peripheral vision, which implies a significant risk if any complication occurs during the complex sub-retinal implant surgery.
Since these technologies transfer visual information electronically, extra functionalities can be integrated. With the Prima, patients can use optical zoom, and image enhancement algorithms have been proposed.
In the future, devices capable of seeing beyond the visible spectrum may emerge, offering thermal imaging and night vision. A device that detects near-infrared has already been tested in primates. However, even if promising, these advanced functionalities will only become relevant when artificial vision, currently basic, evolves significantly.
Meanwhile, considerable challenges related to biomaterials and electronics persist, preventing retinal implants from providing complete and lasting vision restoration. A potentially greater obstacle lies in competing biological solutions, such as stem cells, which are in early stages of human testing. Although these solutions have also faced past disappointments and present major barriers in terms of cell survival and integration, new human retinal cells could eventually surpass bionic eyes as the definitive method for restoring vision.
