UPI Science News  
Fort Lauderdale, FL, May 14 (UPI) -- Researchers demonstrate an electronic
artificial retina that permits vision in blind people.  

At a major vision meeting in Fort Lauderdale, FL, scientists say a 2
millimeter square chip placed on the non-functioning retina allows blind
patients to see spots of light transmitted by an eyeglass-mounted device.  

Still far from the marketplace, researchers say the tests show that the
retinal prosthesis may help restore vision. Dr. Mark Humayun, assistant
professor of ophthalmology at the Johns  Hopkins Hospital, Baltimore, says 15
patients were able to see dots of light, were able to count sequences of
light flashes and could even make out a shape transmitted wirelessly from the
device to the retinal chip. Humayun says the results indicate researchers are
making progress in  developing a prosthesis -- a mechanical, electronic aide
-- akin to the "$6 million Man's" bionic eye.  

But he says doctors are not yet ready to implant the chip in the retina. In
the tests, it was held in place mechanically while light flashes were
emitted. Animal studies will be conducted to determine if the chip can be
safely implanted.  

Humayun says, "We know the patients were really seeing light because they
were able to count the flashes and that correlated with the number of times
we flashed a signal. It appeared to the patients -- who were either totally
blind or could only distinguish between dark and light -- as a bright light.
Some said it was the brightest thing they remember seeing." The patients were
blind due to macular degeneration or retinitis pigmentosa, both caused by
destruction of the retina. Humayun says the studies show that even though the
retina is destroyed, cells which continue the vision process behind the
retina still function and can resume their vision tasks when stimulated.  

