Ophthalmologists and physicists team up to design 'bionic eye'
From: Stanford News Service - 03/30/2005
By: Dawn Levy

Stanford University physicists and eye doctors have designed an
optoelectronic retinal prosthesis system that can stimulate the retina with
resolution corresponding to a visual acuity of 20/80 - sharp enough to orient
yourself toward objects, recognize faces, read large fonts, and watch TV. The
researchers hope their device may someday bring artificial vision to those
blind due to retinal degeneration.  

Degenerative retinal diseases result in death of photoreceptors - rod-shaped
cells at the retina's periphery and cone-shaped cells at its center. The
researchers plan to directly stimulate the layer underneath the dead
photoreceptors. The system consists of a tiny video camera mounted on
transparent "virtual reality" style goggles. There also is a wallet-sized
computer processor, a solar-powered battery implanted in the iris, and a
light-sensing chip implanted in the retina.  

Read the entire news release at:
http://www.stanford.edu/dept/news/pr/2005/pr-retina-033005.html

Link:
Daniel Palanker
http://www.stanford.edu/~palanker/

Retinal Prosthesis
http://www.stanford.edu/~palanker/lab/retinalpros.html

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Designing a 'Bionic Eye'
From: myDNA.com - 04/04/2005
By: Dawn Levy 

Stanford University physicists and ophthalmologists disclosed the design of
an artificial vision system that can stimulate a retina with sharp enough
resolution to enable a visually impaired person to orient himself toward
objects, identify faces, watch television, read large fonts, and live
independently, in the Feb. 22 issue of the Journal of Neural Engineering. The
researchers see the device as being particularly helpful for people left
blind from retinal degeneration, but tests with human subjects are at least
three years away; until then, the system is being tested in rodents. The
system incorporates a small video camera that captures light from objects and
transmits the image to a wallet-sized computer processor that in turn sends
the image to an infrared LED-LCD screen mounted on a pair of transparent
virtual reality style goggles; the goggles reflect the infrared image into
the eye and onto an implanted light-sensitive retinal chip, stimulating its
photodiode array. Software that links image processing to motion detection
takes advantage of the eye's natural image processing strengths and is a key
part of the system's advance over existing technologies. Stanford researcher
Daniel Palanker of the Department of Ophthalmology and the Hansen
Experimental Physics Laboratory says the optimal scheme involves implanting
the chip in the nuclear layer of the degenerated retina, while its placement
on the side of the retina facing the eye's interior attempts to harness the
retina's remaining processing power. The image is amplified and additionally
processed in system hardware external to the eye, while a battery implanted
in the iris powers the device via solar energy. Palanker notes that the
Stanford prosthesis also tracks rapid intermittent eye movements needed to
facilitate the natural perception of images. The design gives users a visual
acuity of 20/80 by employing a maximum pixel density of 2,500 pixels per
millimeter. 

Read the entire article at:
http://www.mydna.com/resources/news/200504/news_20050404_bioeye.html