Rebuilding humans using bionics
Box 1 | Focusing on bionic eyes
Australian research teams are part of the world-wide race to develop a bionic eye.
One system they are developing, uses a microchip implanted on the retina. The microchip receives images via radio waves from a small camera attached to the patient’s glasses. The chip then converts the image data into electrical impulses that travel via electrodes along the optic nerve to the brain, which ‘sees’ the images.
(Image: courtesy of the Bionic Ear Institute, Bionic Vision Australia team member)
Another approach is building on the techniques used in developing the bionic ear that allowed stimulation of nerves in the inner ear, from electrodes lying around the periphery. Instead of a retinal implant, electrodes are wrapped around the outer surface of the eyeball. Images from a camera in the patient’s glasses are fed to a small computer, which might be worn or carried like an MP3 player. The computer converts the images to an electrical signal and sends this to the electrodes, which feed the signal to the optic nerve via an electric field.
Each method has its advantages. The retinal implant will be able to achieve finer resolution but involves eye surgery, which could risk damaging what remaining vision a person might have.
But the Australian teams will have to hurry if they want to win the race to develop a bionic eye. There are some 20 research teams around the world also working on developing the technology. In fact, American research into the bionic eye started back in 1967 when Australian’s were working on the bionic ear. One US company has already tested its Argus II bionic eye, based on a retinal implant, in some 20 patients world-wide. The device reportedly has been able to restore limited sight: one blind man can now see flashes of light and follow the white lines on a road.
One of the challenges for researchers developing retinal implants is to come up with microchips that have more electrodes, which will allow for more pixels and better vision for the person affected.
Related sites
Our approach (Bionic Vision Australia)
About us (Bionic Vision Australia)
How does a bionic eye work? (Australian Bionic Eye Foundation)
How does a ‘bionic eye’ allow blind people to see? (How Stuff Works, USA)
External sites are not endorsed by the Australian Academy of Science.
Posted May 2010.