Scientists Have Created an Artificial Eye for the Visually Impaired
Researchers at the Hong Kong University of Science and Technology have created the world’s first prosthetic eye.
The human eye is a highly sophisticated and integral part of our body. It has a high field of view of 180 degrees, allows us to see things with an astoundingly high-resolution, known to be 576 megapixels, and can dynamically adjust to different types of lighting. For decades, there have been various attempts to replicate the human eye, but many have failed. A major reason for this is the mere shape of the human eye, a sphere. The shape of the human eye is what gives it its high field of view. This shape is difficult to work with, as currently, most advanced camera sensors are flat.
Recently, researchers and scientists led by Zhiyong Fan, a Department of Electronics and Computer Engineering professor at the Hong Kong University of Science and Technology (HKUST), engineered the Electrochemical Eye (EC-Eye), the world’s first biomimetic prosthetic eye. This eye could lead to the restoration of vision to the visually impaired, sharper robotic vision, and more. Current prosthetic technology isn’t very feasible in day-to-day life, as they often require external wiring and glasses, all to offer a poor, 2D vision. Luckily, the team at HKUST believes the artificial eye could offer advanced features like a sharper vision than the human eye and radiation detection in the dark.
How It Works
The retina is a tissue that is located in the back of our eye. It’s responsible for receiving light from the lens on our eye. It then converts that light into neural signals and sends them to the brain via optic nerves. The retina in our eyes consists of tons of light-sensitive cells called photoreceptors. These cells respond to light, so your eyes can dynamically adjust to different types of lighting and can project a sharper image. In photoreceptors, there are two elements: cones and rods. Cones are active when there is lots of lighting, e.g. outside on a sunny day. Rods are active during low-light situations, e.g. outside at night.
Unlike other prosthetic devices, the Electrochemical Eye uses a concave artificial retina, similar to the retina in the human eye. The retina on the artificial eye consists of a highly dense array of nanowire light sensors, which are extremely small wires designed to mimic the photoreceptors on the human retina. These nanowires are made from perovskite, a calcium titanium oxide mineral used to make solar cells. To view the visual signals transmitted from the artificial eye, the team connected the nanowires to liquid metal nerve fibers that act as nerves on a computer. Using this method, they successfully got visual signals to display on a computer.
Advantages
- Sharper quality than the real thing! — Currently, the Electrochemical Eye is far inferior to the human eye in terms of resolution. However, scientists at HKUST are confident that they can increase the quality to a resolution higher than the human eye. This will be achieved by using an even denser array of nanowires, which would allow more light to be captured. In theory, this will allow for sharper images and even better vision in the dark. The response time to a slight change in brightness, for example, the amount of time it takes for your eyes to adjust after stepping out of a movie theater, of the Electrochemical Eye has already surpassed the human eye. According to Technology Networks, the human eye takes 40ms to detect a change in light on a natural photoreceptor and 150ms to recover. The artificial eye only takes an impressive 19.2ms to detect a light change and 23.9ms to recover.
- No blind spots — The retina in the human eye has one spot where there are no photoreceptors. The reason for this is because the spot is a connection point where optic nerves pass through, so it has no space for photoreceptor cells. This results in no image detection, which causes a blind spot, or a small patch where you’re blind. You don’t see a blind spot regularly because the brain “fills” the blind area with a surrounding color. To see for your self, take a look at this site. The Electrochemical Eye has no blind spot because the nanowires are scattered everywhere and are directly connected to the artificial nerve, causing no gap.
In an interview, Professor Fan said:
“In the next step, we plan to further improve the performance, stability and biocompatibility of our device. For prosthesis application, we look forward to collaborating with medical research experts who have the relevant expertise on optometry and ocular prosthesis.”
The Electrochemical Eye is a marvelous invention. It’s far more advanced than any other prosthetic device today. Currently, it falls short of the human eye, but with further improvement, the Electrochemical Eye may surpass the human eye. In my opinion, the future of prosthetics and humanoid robotics depends greatly on this niche little device.
To learn more about this biomimetic eye, read these articles:
