Thanks to the implant, he gained the ability to recognize everyday objects including spoons, bananas, and apples; he could read a clock; and he could read letters, albeit slowly, and they had to be printed extremely large (about 5-8 cm high).
Videos of his abilities and his reactions to his newfound sight are available online.
This subretinal implant is not the only “bionic eye” idea under development, however. Other researchers have been working on using an external camera which transmits information to a relay chip placed on the retina, the "epiretinal” approach.
However, Zrenner’s team argues that their subretinal implant technique has some important advantages. Epiretinal devices have to pre-process the image before sending it to the retina, and patients need time to learn how to process the information that their brain receives, because the camera isn’t able to provide an exact simulation of normal retina outputs.
Zrenner et al’s subretinal method, however, took little “getting used to” because the implant is such a close analogue of the healthy retina. Also, they say that epiretinal approaches have so far only provided up to 60 pixels, as opposed to their 1,500.
Still, the technology has limitations. The image has no color, and it’s much less detailed than normal vision. The sensor has a resolution of 38 by 40 pixels, compared to the 960 by 640 resolution of an iPhone screen.
Being so small, it only covers a small fraction of the normal retinal field. However, this is actually less of a problem than it might first appear, because all of our detailed vision takes place in a tiny part of the retina, called the fovea. By placing the implant where the fovea used to be, the quality of the images was maximized.
The chip also requires an external power supply, so patients need to carry the battery pack and control unit around with them. Finally, they have a fairly hefty wire coming out of the side of their head.
So, at the moment, science is very far from being able to fully restore vision, but it’s still an exciting step forward. Technical improvements are sure to bring higher-quality images in the future.
Other researchers are working on using gene therapy to cure the underlying molecular cause of the disease, preventing the photoreceptors from dying in the first place. This approach has shown promise in animal models, and the results of the first human trials of gene therapy in another genetic eye disease, Leber’s ameurosis, have recently appeared.
So whether this device will become widely used in the treatment of people with diseases like retinitis pigmentosa is unclear. But it joins other emerging technologies, from deep brain stimulation to brain-computer interfaces, which are blurring the boundaries between the nervous system and machines.
Are you a scientist? Have you recently read a peer-reviewed paper that you want to write about? Then contact Mind Matters co-editor Gareth Cook, a Pulitzer prize-winning journalist at the Boston Globe, where he edits the Sunday Ideas section. He can be reached at garethideas AT gmail.com
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9 Comments
Add CommentWe are rapidly approaching the future that we read about in decades-old sci fi novels.
Reply | Report Abuse | Link to thisI would imagine induction would be a better way to power the chip than with a wire. Anyways, sensory bio-tech is showing a lot of promise for widespread application.
Reply | Report Abuse | Link to thisThe eye is anything but perfect. A concave mirror with a sensor dangling at its focal point would do a better job.
Reply | Report Abuse | Link to thisI love developments in the bionic field. It seems that bionics and robotics can solve a wide array of every problem that humans face.
Reply | Report Abuse | Link to thisAnd that, in my opinion, is the purpose of science.
Bionic eye seems especially important because we can replace lots of other parts people may have that are deficient.
The refinement and elaboration in the evolution of the eye can be explained by taking into account that eyes started out very primitive in primitive organisms. As more highly developed species evolved from these primitive ancestors, the structures of the eye also evolved.
Reply | Report Abuse | Link to thisaah...but its the connections that make the difference...
Reply | Report Abuse | Link to thisThanks in advance for your cooperation with the above conditions. I hope you find it useful.It helped me with ocean of knowledge so I really believe you will do much better in the future I appreciate everything you have added to my knowledge base .Degenerations of the outer retina such as retinitis pigmentosa (RP) lead to blindness due to photoreceptor loss. There is a secondary loss of inner retinal cells but significant numbers of bipolar and ganglion cells remain intact for many years. Currently, no therapeutic option to restore vision in these blind subjects is available. Short-term pattern electrical stimulation of the retina using implanted electrode arrays in subjects blind from RP showed that ambulatory vision and limited character recognition are possible.
Reply | Report Abuse | Link to thisRegards,
<a href="http://www.thechiropages.com/">chiropractor</a>
okay, but what will this do for my biometric door lock? Can you buy the same model as I have or will we have rotating iris'?
Reply | Report Abuse | Link to thisDon't forget having emerald gray green eyes with yellow highlights!
How will the police know if I've been drinking?
Will I have to replace it with a Compact Fluorescent version?
Prove it.
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