Vision-Correcting Displays [video](youtube.com) |
Vision-Correcting Displays [video](youtube.com) |
The implications are bigger than vision correction - LF display can reconstruct actual 3d images, as opposed to the stereo images being marketed as "3d" today. Stereo displays give two different pictures to two different eyes, but the don't provide perspective shift (the picture doesn't change when you move your head left and right), and they don't provide different focal planes (your eyes focus on the screen plane regardless of how far the object is supposed to be, creating a dissonance between the distance inferred from the angle between the eyes and the focusing distance).
Douglas Lanman, the researcher behind this technology work at Nvidia was hired a few months ago by Oculus VR.
http://www.nytimes.com/2014/07/15/science/taking-real-life-s...
One use case example was a guy in a car with GPS navigation. So he can then see the GPS nav but how does he drive if he can't see properly!?
And speaking as one of the people whose vision defect can't be corrected by glasses, but only by uncomfortable contact lenses, there'd be immense value to me in a computer I can use without lenses - especially since reading on a screen is basically the only thing I need the damn things for while I'm at home. For someone whose work is mostly computer-based, you might be able to get away with taking your lenses out for the entire day and only wear them for the drive to work and back.
So they would also not be able to see their speedometer, or their fuel guage...
This is a technological solution looking for problems that are far more conveniently solved by conventional means.
Many people have vision problems where the eye can't easily focus on a variety of distances. So if you have glasses, they're set up to make focusing on one distance easy, but things closer or farther (if that distance is not "infinity") is more difficult. I have progressive bifocals to get some amount of varying correction with distance, but this is thrown off for computers since they take up more of your field of vision than a book. (I also find looking at my phone through the bottom of my glasses to be pretty awkward, even though I've had bifocals since elementary school.)
One solution is an extra pair of glasses for computer work, but this is annoying because you can't get up and go to the bathroom without changing glasses. If the computer monitor were set to add the extra correction between my normal prescription and the intermediate distance prescription, my life would be much better. (Same for my phone.)
Right now, I can pretty much focus without using anything more than my distance prescription, but as I get older, this will become more and more difficult. So I'm pretty excited about this; less eyestrain is always good.
Also, the ability to tweak the correction in software is great. Where I have my monitor isn't quite what the optometrist was expecting when I had my computer glasses made, so I have to change positions to use them. With control in software, I could just adjust some config file somewhere when I rearrange my desk.
Sounds much simpler than trying to ensure a continuous supply of glasses for 500 energetic kids
Although I'm skeptical that third world countries will have access to high tech vision correcting tablets but not eyeglasses.
Would be a neat touch. I like connected appliances that aren't. (if that makes sense)
So, while I can use my phone just fine, you can't cause it's calibrated to correct my vision deficiency. I guess that it can be used on something extremely personal; like a phone, but I don't see it becoming main stream for most displays, like a shared tablet or a computer or something.
In their case they are sysnthesizing a light field which inverses the aberration everywhere, you'd be doing a inverse filter specifically for your viewpoint.
I don't know how good the results would be in practice, would I would like to see someone try.
On a serious note, this does seem like a dumb idea. Why would you create a million corrective devices for the myriad objects in the real world. Why would you not rather create something small and portable that you could apply to all those objects equally?
OH wait, they have that. They're called eyeglasses, I think.
I guess this is a limitation of the plasticity of our brains. People who have hearing or vision or other losses as young children adapt faster and better than people who have these losses when older.
It would be interesting to understand if young children with vision deficits can learn to see better with time.
My personal recollection is that I had NO idea things were blurry until my first visit to the optometrist when they put glasses on me. Things were so SHARP!
I think the core of this is that out adaptability depends on sensori-motor loops. We can calibrate our responses for faulty sensors, but we don't correct just for the sake of correctness.
Adaptive optics requires more than just algorithms -- the algorithms' output are fed into a rapidly moving reflective surface to de-blur the incoming light [1] -- so this is a bad analogy. You might be thinking of some of the deconvolution algorithms [2] that the Hubble Space Telescope used before its "eyeglasses" were installed in 1993 to improve its flawed images.
[1] "Adaptive optics works by measuring the distortions in a wavefront and compensating for them with a device that corrects those errors such as a deformable mirror or a liquid crystal array." https://en.wikipedia.org/wiki/Adaptive_optics
[2] "The error was well characterized and stable, enabling astronomers to optimize the results obtained using sophisticated image processing techniques such as deconvolution." https://en.wikipedia.org/wiki/Hubble_Space_Telescope#Flawed_...
By no means an expert in this area but I would think the best that could be done with this type of post processing would likely amount to applying a highly specialized "Find Edges"/"Sharpen" filter in Photoshop to a blurred photo (except at a really high resolution and at > 60 frames per second).
An interesting possibility with that kind of neural-level post-processing could be an on-demand digital-zoom effect so you could do a 2X-32X zoom on a faraway road sign or to "zoom in" to something really close at a macroscopic level (for surgeons/jewelers).
"Deconvolution in humans
A huge fraction of our brain is devoted to vision. One of the neglected features of our visual system is that the raw image falling on the retina is severely blurred: while most people can see with a resolution of about 1 arcminute (one sixtieth of a degree) under any daylight conditions, bright or dim, the image on our retina is blurred through a point spread function of width as large as 5 arcminutes (Wald and Grison, 1947; Howarth and Bradley , 1986). It is amazing that we are able to resolve pixels that are twenty-five times smaller in area than the blob produced on our retina by any point source. Isaac Newton was aware of this conundrum. It's hard to make a lens that does not have chromatic aberration, and our cornea and lens, like a lens made of ordinary glass, refract blue light more strongly than red. Typically our eyes focus correctly for the middle of the visible spectrum (green), so if..."
I recommend the read for those interested. There's even an experiment you can do yourself to experience your own eyes limitations!
However, until it is universally installed in cars and easily adjusted for your personal needs when moving from car to car, I doubt many people will be throwing away their bi/tri-focals in favor of lenses for distance only.
The video mentions both the GPS and speedometer as potential targets for this technology. Giving it some thought and being close to the age where I might benefit from this, it isn't such a bad idea after all.
(Although I'm short-sighted, so the arguments above don't apply to me anyway.)
Essentially, I'm getting close to doing the opposite of what most people do with reading glasses. For now, I do most minor reading tasks and my work with my glasses on, but for lengthy reading I take them off. Over time, I'm sure, I'll end up taking them off (or looking below my glasses) for almost every reading task, and eventually for work as well.
In the end, though, I don't think the technology will be likely to really solve the issue for me, except to correct a few displays for my corrected vision. I have to pin most of my hopes, at the moment, on improvements in surgery and eventually being able to afford the surgery.