Bionic Eyes for Everyone
Rob Riggs writes "As seen on this SlashCode using site, scientists at the University of Rochester are working on a project to bring adaptive optics, technology used in ground-based astronomy, to the human eye. They expect to achieve 20/10 vision and enhanced contrast for everyone, but this article claims 20/2.5 is ultimately possible." The best thing about this story is that the submitter picked the rarely-used "Upgrades" category for it.
How does the 20 - scale work anyway? Is there a maximum (20/0)? Is it linear or logarithmic with respect to the quality of your vision? Is the denominator just a measurement? Why 20, is it just normalized to average vision?
Disclaimer: I'm no optha^M^M^Mopthi^M^M^M eye doctor, but here's how I understand it to work:
Your vision in feet / Normal vision in feet
For example, if you have 20/10, that means you can see at 20' what most people have to get within 10' in order to see. (A street sign, breast size, writing on the wall, whatever.)
At my last checkup, I had 20/40, meaning I have worse than average vision. I have to be only 20' away from the chart to get the same results that the normal person can see within 40'.
A good way to explain the theoretical max of 20/2.5 that they're talking about is to think about computer monitors. If you sit 2.5' away from your 17" monitor, you can read everything fine. These robotic eyes would allow you to read the same text on the same monitor, standing TWENTY FEET AWAY, with the exact same accuracy as someone sitting just 2.5' away. That's astounding.
Or think of it another way: it's pretty hard to get within 2.5' of Natalie Portman, but if you plunk down the money for these roboeyes, you only have to get 20' away in order to find out if she's really got perfect skin or not.
What's your damage, Heather?
could become useful if you're surrounded by a bunch of supermodels =)
Yes, being in the glamorous world of system administration, that situation comes up often.
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Adaptive optics is meant to correct tinier flaws in the curvature of the lens of the eye. As the article said, current Lasik machines typically only correct for astigmatism and prescription, but in a fairly smooth manner over the surface of the eye. All this does is provide a more detailed map of the eye. "Bionic" vision, it isn't. I ended up with 20/15 vision after standard Lasik, and no matter what the people who get all excited about this technology think about it, the retina doesn't have enough resolution in terms of rods/cones for anything better than 20/12 vision. 20/10 could only happen with someone who naturally had a gene for a higher retinal density. If you are lacking rods/cones in the eye, no amount of corrective optics in the lens can help. Its like upgrading your video card so you can do 1920x1280x24bit and only having a 640x480 VGA monitor. Nothing but replacing the monitor can help. Along the same lines, nothing but replacing the retina can help if the source of poor vision comes from it, not a misshapen lens. Don't fret though, this technology won't help, but give it ten years, there are already implanted artificial retinas, and I wouldn't be suprised if in ten years bioengineered replacement eyes aren't happening as well. In both of those cases, as long as the nerve density within the optic nerve is normal, then when technology gets advanced enough it can be fixed. (Plus its worth remembering that the area of the retina that needs to be "corrected" to achieve perfect vision is very small, a millimeter or two in diameter. Peripheral vision in virtually everyone is very bad, dozens, if not hundreds, of times worse than their normal vision -- rod/cone and nerve density both are very low outside the very center of the retina)
I have one good eye and one not so good eye, so norally 95% of my vision is with my good eye. Working on my car I got a piece of rust in the good eye and it was subsequently bandaged for a week. The strangest things happened...I really could see fine but the processing of the info was terrible, especially at first...my judgement of position and velocity was way off, and this was NOT due to a lack of depth perception, as I can operate with just my good eye fine.
The most startling occurrence was when I was later brave enough to drive and I was behind a car on the highway. His brake lights came on, in a flash I knew he was stopping but with only my bad eye, not used to processing this kind of info, I couldn't determine how quickly he was decelerating, tapping his brakes or jamming them. I panicked and ripped the bandage off my other eye and instantly I "understood" how everything was moving around me.
New optics would be great, but I guess I really want a CPU upgrade :)
SuperID
This might not be the place to discuss the pathology of diabetic retinopathy in detail, but I'll babble enough so you can understand the therapy for it. Changes in the blood vessels which supply the retina in the early stages of this condition lead to inefficient oxygen delivery to the active tissues -- ischemia. As a response, the blood vessels branch, grow, and proliferate to combat this. This is a Bad Thing, because the new vessels can get in the way of the retinal surface, or break causing haemmorhages, retinal detatchment.
The treatment of choice for this is a laser therapy, different from the Lasix/Excimer cornea-modifying modalities, which goes by the super-funky name "pan-retinal laser photocoagulation" (I love saying that) where peripheral parts of the retina are zapped with an argon laser. This reduces the metabolic oxygen requirement for the peripheral retina... such that the more important central structures are spared. Done right, and at the right time, this can reduce the incidence of severe visual loss by 50%, and as much as 90% in some studies.
I don't want to sound offtopic (discussing a different laser therapy), but I'm concerned that someone who is diabetic might fall into this thread and assume that all laser therapies are the same, and thus make judgements about photocoagulation therapy based on the concerns raised about Excimer.
--- [DrPsycho] Coping with reality since 1975.
-DrPsycho - Coping with reality since 1975