Solar-Powered Augmented Reality Contact Lenses 213
ByronScott writes "Want eyesight that could put your neighborhood cyborg to shame? Well, University of Washington professor Babak Amir Parviz and his students are working on solar-powered contact lenses embedded with hundreds of semitransparent LEDs, letting wearers experience augmented reality right through their eyes. If their research proves successful, the applications — from health monitoring to gameplay to just plain bionic sight — could be endless."
Problems (Score:5, Informative)
There are several difficulties with this type of system that have prevented it from becoming a reality. Here are a few:
1. This is too close to the eye to be able to resolve focus in most situations. The light isn't collimated or directional (it appears to be focused with some sort of "microlens" system), so one LED turned on can spread out to stimulate a wide patch of retinal cells. With any regular LED system you'd just see a big blur. For information requiring a single light this isn't a problem (flash an LED on/off under certain conditions, or change the color) but anything more will require something which can project cleanly onto the retina. This is not a trivial problem.
2. The detail-oriented part of your retina is near the center, in a part called the fovea [wikipedia.org]. While you think your vision is equally clear across a wide range, this is actually a trick of your brain. Your eyes are quite sensitive to rapid movement (low latency) on the edges, and more sensitive to detail in the center. When observing fine detail such as text, your eye actually "scans" an area and forms a larger, detailed image from the composite. Even if you could project the light cleanly 1:1 onto the retina, for any textual/HUD information you'd have to track eye motion very precisely and provide the information that the brain "expects" to see at each point. And again, the light has to be projected onto a very small part of the retina.
3. Retinal cells can get easily overstimulated, much like the burn-in on old CRTs. Even when looking at one object of normal intensity for any period of time longer than a few seconds, your eye will "jitter" back and forth. This involuntary movement is called nystagmus [wikipedia.org], and your brain compensates for it. (The rhythm changes when alcohol or drugs are ingested, which is why nystagmus tests are part of a DUI test.) Lab tests have shown that when the eye is physically restrained from moving in this way, objects effectively become invisible to the subject. So any 1:1 projection would also have to track nystagmus and then "jitter" in the same way as the eye, or the conveyed information would also become invisible.
Re:Bullcrap (Score:5, Informative)
Get back to us when you have some sorta prototype.
I think you're in the wrong part of the internet. This is news for nerds. Really cool tech, even if it might turn out to be vaporware, qualifies.
Re:Problems (Score:3, Informative)
> 1. You say each LED is not collimated or directional but then you mention a microlens system. What does this microlens do, if not collimate?
Think. Why are lasers of such importance? Why can't we just use LEDs with mirrors and lenses to accomplish the same thing as lasers in optical drives? The reasons here are very similar. There will be leakage, there will be diffraction, and the light won't focus cleanly on a single region of the retina.
> 2. Contact lenses move with the eye.
That's exactly the problem. When your eyes move the patterns from the outside world "move" across the retina, and the visual-optical response system can function properly. This set of lights is stuck to the front of your eyeball, so the light emitted by the LED array does not move. The way to solve this is to have some very intelligent circuitry that can pan the LED patterns on the display along with the eye movements.
Normal contact lenses do not produce light. They act as a surface to modify the shape of the cornea in order to fix aberrations in the lens system. (The lens inside your eye is one source of refraction, but the boundary of your cornea with air is the other major one. This is why refractive eye surgery can correct your vision.)
Does this make more sense?
Re:Looks Pretty Vapory (Score:4, Informative)
If you follow the trail of blog references, you end up here [justgetthere.us], which is apparently the blog of one of the researchers. It has far more information. To your particular point: "In recent trials, rabbits wore lenses containing metal circuit structures for 20 minutes at a time with no adverse effects. ... We’ve mainly pursued the active approach and have produced lenses that can accommodate an 8-by-8 array of LEDs. For now, active pixels are easier to attach to lenses. But using passive pixels would significantly reduce the contact’s overall power needs—if we can figure out how to make the pixels smaller, higher in contrast, and capable of reacting quickly to external signals."
So it's probably a little bit further along than your teleportation research. Are you using rabbits too?