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Thursday, September 24, 2009

You Want To Stick A Chip Where?

So - remember when I said Augmented people will be here sooner than expected?  Here's another step closer: Scientists have developed a chip that implants in the eye and feeds signals to the optic nerve at the retina.  They are not claiming they will be able to restore full sight to a person, and with good reason - our eye actually has totally piss-poor resolution, and even if they managed to hit every optic nerve ending the total resolution would be only a few thousand pixels...

This is because the eye doesn't work like a camera, where each pixel of a scene corresponds to a "pixel" or nerve ending on the optic nerve.  Our eyes perform "saccades' which are rapid movements, and the brain is fast enough (and the saccades are accurately enough performed) to map a composite map into the brain.  The eye scans the scene and builds it up a few thousand pixels at a time.

Our brains also fill in a lot of the tedious detail which isn't in the center of our vision, with generic extrapolations.  The reason you don't notice is because it's not in your field of attention - and when you look at that part of the scene, it becomes the center of your field of attention and therefore the eye/brain start to record that part in more detail.

But it's not hard to track saccades, or even just the nerve impulses that tell the eye to saccade, and therefore the first scientists to build a chip that can map a scene onto that extended canvas that our brains use by simulating what happens naturally for sighted people, then full field vision will be possible.  It's not too hard to emulate.

That's why, for the moment, those external devices that project back into the retina are effective, and are better than any implanted chip can be. The eye saccades and picture source in this case is not fixed with respect to the eye so it gets "swept" across the retina.

And of course, defence forces are also going to be interested in this kind of technology, because again, it provides a much needed situational awareness tool for their troops on the spot, the kind that can't be dropped on the floor and thus lost.

Me, I'm imagining myself at over 50 years of age being fitted with something like that for browsing the web, and i can see one, somewhat less obvious problem: As we age, our eyes lose conformity and our eyesight becomes limited.  Because the implant is behind the cornea and lens which cause that blurriness, any image I see from it will be crystal clear and sharp, and focused at whatever distance. Without me needing glasses or correction.

If I'm only overlaying a web browser on my vision, I'm pretty sure the experience of seeing one object apparently at 2m distance being sharp and clear while a physical object beside it is blurred, would probably induce headaches and nausea, and problems seeing properly.

So for the moment, external retinal projectors are still the best bet for general augmented vision.

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