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Coming Soon, Super Vision
lil_nohreaga writes "Wired is reporting that several companies are developing electronically controlled lenses to provide enhanced vision. From the article: Thanks to technologies created for astronomical telescopes and spy satellites, aberrometers can map a person's eye with extreme accuracy. Lasers bounce off the back of the eyeball, and structures in the eye scatter the resulting beam of light."
Imagine what a rifle scope built with this technology would do for Soldiers on the battlefield. Well-aimed fire is one of the primary factors that decides who wins in a firefight. The military would definitely profit from wide-spread use of super vision lenses.
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I think (some) people are getting a bit too excited about this without considering the downsides. It's already possible to give people much-greater-than-average vision using laser eye surgery, and has been for a while, but it's not usually done, simply because those it was found out that when your vision is *too* good, it'll start to irritate you after a while - you'll get headaches, dizzy spells etc.
So... superhuman vision might be useful on occasion, for short periods of time, but if you think that we're all gonna wear contacts that will literally give us a hawk's vision in 20 years, think again. It won't happen.
quidquid latine dictum sit altum videtur.
Using wavefront sensors to fully characterize your eye is not new. LASIK patients get that treatment now -- you look into an autocollimator that includes a Shack-Hartmann sensor, and it reads out all the high-order aberrations in your eye. The LASIK treatment then gets rid of all those aberrations, so that after correction your eye could in principle be "perfect" -- limited only by quantum uncertainty of the photons entering your pupil.[In practice that's not the case, because the act of cutting your cornea and letting it heal introduces a low level of new aberrations that weren't present when your eye was characterized in the first place].
If wavefront sensing is so easy and painless, why don't we all have super-duper glasses to fix our vision? Historically, it's because high order lenses are hard to grind, but more recently it's because your glasses can't be aligned with your eye very well. You could make high-order corrective glasses out of the usual glass or polycarbonate or whatever, but they would only work if you looked straight through them: if you turned your eyes to look sideways, the corrective aberrations in the lenses would no longer line up with the aberrations in your cornea, and your vision would be worse than with conventional glasses. If you have astigmatism you can get that effect now by turning your glasses 90 degrees as you look through them: at 90 degree rotation, the cylindrical correction actually worsens your astigmatism rather than correcting it. high order terms are more sensitive to angular and positional alignment.
Contact lenses are better since they are attached to your cornea and therefore stay approximately aligned -- but they're not affixed to your eye, they sort of drift around in there. That's one reason that astigmatic contacts (a relatively new product, BTW) are only available in 10 degree increments of correction angle -- they don't line up any better than that. The only thing that stays really fixed relative to your cornea is, well, your cornea -- which is why high-order correction is feasible for LASIK.
So to make your super-duper glasses work right you would have to mount a small camera under the frame, pointed back at your eye. The camera would have to back out the motion of the eye and correct the active pixels in the lens as you looked around. That may be what these guys are doing, but TFM didn't mention it. Without that sort of feedback, high order correction isn't likely to work well.
BTW, wavefront sensors appear like magic to lots of folks but they aren't. Those eye autofocusers at the optometrist work by autocollimation: if your eye is perfectly focused, then a beam coming in should be focused to a single point on the retina, and scattered light from the retina should then be refocused into a beam that goes straight back where it came from. The autocollimator adjusts an external lens assembly until the beam coming back out of your eye is nice and clean. Wavefront sensors use a bug-eye lens to produce (say) 25 little images, each of which records the beam coming out of a small patch of your pupil. If the eye is in focus, then all the little images should line up. If it's not, then they are misaligned. It's that simple.