Bionic Eyes: Restoring Sight with Microchips
- Saniya Jassal
- 1 day ago
- 3 min read
The idea of restoring sight through technology has long lived in science fiction, but in recent years, it has begun to take form in the real world. With more than 285 million people globally living with vision impairment, researchers are racing to develop visual prostheses, which are devices that convert visual information into electrical signals to help individuals with profound vision loss perceive the world again.
How Bionic Eyes Work
Bionic eyes, formally known as visual prostheses, use microchips and electrical stimulation to mimic the natural processes of the visual system. These devices don't restore vision in the traditional sense, but they create simulated visual experiences, often described by patients as flashes of light or phosphenes. Over time, and with training, users learn to interpret these electrical signals as meaningful shapes or objects.
Types of Visual Prostheses
One common approach targets the retina, where light-sensitive photoreceptors normally begin the visual process. In people with diseases like retinitis pigmentosa (RP) or age-related macular degeneration (AMD), these photoreceptors are often damaged or lost. Retinal prostheses are designed to bypass the damaged cells and stimulate the remaining layers to relay signals to the brain.
The Argus II is one example of this technology. It consists of a camera mounted on glasses, which captures images and transmits them wirelessly to an electrode array implanted on the retina. This setup enables users to distinguish light from dark and recognize large shapes. Though it does not produce clear vision, the system helps users navigate and identify key visual cues in their environment. The Argus II was approved for use in Canada and the United States but is no longer being supported by its manufacturer.
Another class of devices, subretinal prostheses, are placed beneath the retina and use a different method. These devices, such as the Alpha IMS and Alpha AMS, use photodiodes that mimic the function of photoreceptors by converting light into electrical impulses. Unlike the Argus II, they don’t rely on external cameras, which allows more natural eye movement but can limit processing power. These subretinal implants are currently approved in Europe.
A third experimental approach involves suprachoroidal implants, which are placed between the retina and the outer layer of the eye. Though not yet approved, early research suggests they may offer new pathways for vision restoration with fewer surgical risks.
Beyond the Eye: Cortical Implants
When the retina or optic nerve is too damaged to function, researchers have explored devices that bypass the eye altogether. Cortical prostheses, such as the Orion system or Gennaris headset, stimulate the visual cortex directly. This strategy could benefit individuals with a wide range of conditions, including optic nerve damage, glaucoma, and trauma. These systems also rely on external cameras to gather visual data and deliver it to electrodes implanted on the surface of the brain.
The Future of Bionic Vision
The technology behind these implants is grounded in the brain’s ability to perceive phosphenes, which are bursts of light triggered by electrical signals rather than by natural light. By manipulating these signals with precision, researchers can guide users through a new visual language. With enough training, some users are able to recognize basic shapes, identify letters, and detect movement, representing a form of ultra-low vision.
Current research focuses on improving resolution, expanding visual fields, reducing device size, and increasing the number of electrodes for more detailed stimulation. Investigational devices like PRIMA, IRIS II, and the Phoenix 99 are pushing boundaries and bringing more refined vision closer to reality.
While bionic eyes are still in the early stages of functional use, their existence represents a major milestone in biomedical innovation. These microchip-powered implants not only restore fragments of sight but also redefine our understanding of vision and showcase the remarkable adaptability of the human brain.
References
Fighting Blindness Canada. (2024). The Bionic Eye. Fighting Blindness Canada (FBC). https://www.fightingblindness.ca/resources/the-bionic-eye/
Guymer, R., Brandli, A., Luu, C., & Ayton, L. (2016). Progress in the clinical development and utilization of vision prostheses: an update. Eye and Brain, 15. https://doi.org/10.2147/eb.s70822
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