Blind people have long desired for brightness, but scientists don't have the technology. To bring that one step closer to reality, Zhiyong Fan, a material scientist of the Hong Kong University of Science and Technology, developed a new artificial eye recently. The device, which is about as sensitive to light and has sharper vision and a faster reaction time than a real eyeball, may outperform human eyes.
The human eye owes its wide field of view and clear eyesight to the retina（视网膜）—an area at the back of the eyeball covered in light-detecting cells. The design for a new artificial eye is based on the structure of the human eye and uses a friendly light-sensitive material. At the back of the eyeball, an artificial retina is lined with Nan scale light sensors（纳米级光感器）. Those sensors measure light that passes through the lens（晶状体） at the front of the eye. Wires attached to the back of the retina send signals from those sensors to the processor, similar to the way nerve networks connect the eyeball to the brain.
"In the future, we can use this to replace damaged human eyes," says the lead designer. In theory, this artificial eye could see more clearly than the human eye, because the artificial retina contains about 460 million light sensors per square centimeter while a real retina has about 10 million light-detecting cells per square centimeter. Besides, the artificial eye ball records changes in lighting faster than human eyes can —within about 30 to 40 milliseconds, rather than 40 to 150 milliseconds. Although its 100-degree field of view isn't as broad as the 150 degrees a human eye can take in, the device can see as well as the human eye in poor light.
Hongrui Jiang, an electrical engineer at the University of Wisconsin, though, thinks engineers need a much more practical and efficient way to produce vast series of tiny wires on the back of the artificial eyeball to give it superhuman sight, which is super hard to achieve.
