Saturday, November 6, 2010

I See You

Could new microchips implanted in the back of the eye restore sight to the blind?

Image Credit: Iris
Can you imagine not being able to see? If you're not blind, this can be much harder to imagine than you think. As humans, former tree swinging apes really, our eyesight developed to help locate the most colorful looking fruit for consumption, or to judge the distance between trees; fatal consequences arising if not done properly. Unfortunately, blindness in various forms afflicts millions worldwide and is by no means a homogeneous condition, impaired eyesight below a certain threshold can be considered functionally blind and can leave one severely handicapped, even if minimal vision remains. Now, a new study by the Royal Society of Biological Sciences shows that certain forms of blindness can be cured guessed it, computer chips and implants!

Three patients with functional blindness due to hereditary retinal dystrophy were examined. They all had some form of vision before their respective conditions and eventually lost their vision with the exception that they could still detect intense light levels, besides this they were functionally blind.

The treatment method being studied to try to improve their vision loss consisted of a small implantable microchip containing 1500 microscopic photo-diodes, a small type of light detector capable of converting light into small electric currents. These diodes were surgically implanted onto their damaged retinas (the light sensing organ of the eye), and connected to the various retinal nerve fibres. The whole principle being to replace their defective retinas with artificial look-a-likes (get it, look a-likes). When light struck these photo-diodes, they produced an electrical pulse that was detected by the bipolar cells of the retina, which could then theoretically be perceived by the brain as sight.

What was discovered was quite astonishing. After implantation, three completely blind persons could now discern objects by sight alone and name them too, locate objects in a visual field, and discern various shades of gray. They were also able to talk to and approach people in a room and properly identify those people. And they were also able to read to an extent (albeit with large font). To go from functionally blind to being able to do the above is nothing short of amazing.

The potential for future development is also quite large. What was discovered was that increasing the amount of photo-diodes increased the visual perception, contrast, and resolution of the image they were seeing. With the ever decreasing size of microelectronics, I could see this technology develop to give the blind the ability to see the equivalent of a black and white movie in the near future, and eventually (somehow) the ability to see colour. However, questions arise. What would happen if you give someone their sight who has never seen before, that is if they have been blind from birth. I'm curious as to how they would perceive the world or if their brain still interprets images the same way. For now I think I'll just sit back and be grateful that these retinal implants work as well as they do. Regardless, this is once again another amazing development which has the ability to eliminate a condition that has plagued humanity since nearly forever. I for one will not miss it when it goes.

You can read the original research paper by the RSBS here:

Image Credit: Iris Irish battle to defeat blindness.  

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