Posts tagged color blindness
Articles and news from the latest research reports.
Neil Harbisson Is A Cyborg Who Hears More Of The World Than We See
What would your world be like if you couldn’t see color? For artist Neil Harbisson, a rare condition known as achromatopsia that made him completely color blind rendered that question meaningless. Not being able to see color at all meant that there was no blue in the sky or green in grass, and these descriptions were merely something to be taken on faith or memorized to get the correct answers in school.
But Neil’s life would change drastically when he met computer scientist Adam Montandon and with help from a few others, they developed the eyeborg, an electronic eye that transforms colors into sounds. Colors became meaningful for Neil in an experiential way, but one that was fundamentally different than how others described them.
This augmentation device wasn’t like a set of headphones that he could put on when he wanted to “listen” to the world around him, but became a permanent part of who he was. Though he had to memorize how the sounds corresponded to certain colors, in time the sounds became part of his perception and the way he “sees” the world. He even started to expand the range of what he could “see”, so that wavelengths of light outside of the visible range could be perceived.
In other words, he became cybernetic.
Not being readily accepted into society prompted the birth of a mission, as he explains in the phenomenal short film “Cyborg Foundation” that has won the Grand Jury Prize in GE’s $200,000 Focus Forward Filmmaker competition.
Neil recently gave a fascinating talk at TEDGlobal2012 describing how his life is different, including how he can “eat my favorite song: I can compose music with food” and “before I used to dress in a way that it looked good — now I dress in a way that it sounds good.” The foundation he co-launched aims to advocate the development and adoption of cybernetics into society. “Life will be much more exciting when we stop creating applications for mobile phones and start creating them for our body.”
Vision cells, not brain, to blame for colour blindness
The real culprits of colour blindness are vision cells rather than unusual wiring in the eye and brain, recent research has shown.
The discovery brings scientists a step closer to restoring full colour vision for people who are colour blind – a condition that affects close to two million Australians, says Professor Paul Martin from The Vision Centre and The University of Sydney.
It may also help pave the way for an answer to one of the most common causes of blindness – age-related macular degeneration (AMD), which accounts for half of the legal blindness cases in Australia.
“There are millions of cones in our eyes – vision cells that pick up bright light and allow us to see colour,” Prof. Martin says. “They are nicknamed red, green and blue cones because they are sensitive to different wavelengths of light.
“We now know that in the macular region of the eye, each cone has its own ’private line’ into the optic nerve and the brain. Just as a painter can mix from three tubes of paint to produce a wide and vivid palette, our brain uses the ‘private lines’ from the three cone types to create thousands of colour sensations.
Scientists previously thought that full colour vision depends on specialised nerve wiring in the eye and brain, but animal studies show that the wiring is identical for monkeys whether they have normal or abnormal colour vision, Prof. Martin says.
“This tells us that there’s nothing wrong in the brain – it’s only working with the signals that it receives on the ‘private lines’,” he says. “So the only difference in normal and abnormal colour vision is caused by the first stage of sight, which points to faulty cones. Either they have failed to develop, or else they are picking up abnormal wavelengths.
“Now that we know faulty wiring isn’t the cause, we can concentrate on fixing the cones, which are controlled by genes – and thus prone to mutation or mistakes during cell replication. There are already promising results from gene therapy as a way to restore full colour vision in colour blind monkeys.”
“While we have still have some way to go, the benefits of this gene therapy – if successful – can potentially extend beyond providing complete colour vision,” he says.
“If we can get these genes to work in human eyes, it means that the same approach might be possible for other visual problems – including blinding diseases such as macular degeneration.”
"In macular degeneration, energy supplies to the macula can’t keep up with demand. So the ‘private line’ system must be very energy-intensive. Gene therapy could be used to turn down the cones’ energy demand, or to increase energy supply from supporting cells to cone cells,” Prof. Martin says.
“Together with clinical researchers at the Save Sight Institute, we are now working hard to find out exactly how many ‘private lines’ there are in humans. That can point us to where energy demand is highest and we can target gene therapy to the right place.
"So animal research on ‘private lines’ for colour vision has given new clues for understanding one of the most important visual diseases – macular degeneration – in humans."
(Source: scinews.com.au)