Making Artificial Vision Look More Natural

Making Artificial Vision Look More Natural

NOTE: This is an overview of a National Eye Institute Press Release. Click here to read the entire Press Release.

Several projects have provided blind patients with partial vision. While these advances are worthwhile and significant, they do not offer the high resolution that sighted humans possess. The NIH funded project described in this article is the first step toward meeting that goal.

A team based at Stanford University in California is working to improve the technology by targeting specific cells in the retina. “We’ve found that we can reproduce natural patterns of activity in the retina with exquisite precision,” said E.J. Chichilnisky, Ph.D., a professor of neurosurgery at Stanford’s School of Medicine and Hansen Experimental Physics Laboratory.

The new study shows that patterned electrical stimulation can activate the right cells at the right time in isolated retinal tissue. The lead author, Lauren Jepson, Ph.D., and Dr. Chichilniski collaborated with researchers at the University of California, San Diego, the Santa Cruz Institute for Particle Physics, and the AGH University of Science and Technology in Krakow, Poland. They focused their efforts on a type of retinal ganglion cell called parasol cells, known to be important for detecting movement, and its direction and speed, within a visual scene.

The researchers placed patches of retina on a 61-electrode grid, then sent out pulses at each of the electrodes and listened for cells to respond. This enabled them to identify the parasol cells and established the amount of stimulation required to activate each of the cells. Finally, they electrically stimulated the cells in this same pattern and were able to reproduce the same waves of parasol cell activity they observed with the moving image.

Several types of retinal prostheses are under development, based on these studies. The Argus II, developed by Second sight Therapeutics with more than $25 million in funding from the National Eye Institute (NEI), was approved in the U.S. in 2013 for treating retinitis pigmentosa. Such advances could help make artificial vision more natural, and could be applied to other types of prosthetic devices, too, such as those being studied to help paralyzed individuals regain movement.