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It's reasonably well known (or will be, when you've finished reading this sentence) that the human brain can adapt to an inverted visual field. People fitted with inverting glasses are initially inept and unable to perform vision-related tasks in what appears to be an upside-down world. But, after
an adaptation period of a few days, the brain learns to flip the image, and the wearer sees the world normally again.
But what other miracles can the visual system perform? How plastic is the brain's visual cortex? Could it adapt to, say, a compound eye?
Compound eyes come in many types. In some cases, each facet registers only light intensity - a single "pixel". But in other types of compound eye, each facet is an image-forming eye in its own right. It's this second type of eye that is of interest here.
So, the experiment is to make eyeglasses which produce, on the retina, multiple small, identical images. Each image is just a shrunken version of the full visual field. Thus, each small part of the retina becomes a complete "eye", but with necessarily poor resolution. We might tile the retina with four, sixteen or a hundred small images in this way.
Initially, of course, the wearer would just see multiple low-res repeats of the scene before them. But, given time, would the brain adjust to this new format, and fuse the images into a single, high-resolution one?
One problem is that the human retina has greatest resolution only in a fairly small part of the retina (the fovea) - you normally only see a small part of the visual field in detail, and your brain creates the illusion of uniform detail. With MaxCo's "BugGlasses", the small image that hits the fovea will contribute most to the perceived scene. But, collectively, the peripheral images can contribute additional acuity.
An interesting corollary to this is that the whole visual field would be seen with the same resolution (since the whole field would be imaged by the fovea, but also by all the peripheral parts of the retina). Your peripheral vision would be as acute (or as non-acute) as your central vision.
It might even be possible to make these glasses useful. For instance, if some of the glasses' facets were polarized, you would (if your brain fused the images successfully) be able to perceive polarisation as an overlay on an otherwise normal visual field.
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Feed a negative color view of the back of the user's head as a half-transparent overlay and see whether he can adapt to a 114+114 degree field of view. Or fish-eye for 360 degrees. |
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Dammit! I pictured it fully and now my head hurts. I think I sprained something in there. Hopefully it's just a spasm. |
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You'd lose all distance vision... but be able to avoid getting swatted like nobody's business. |
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//You'd lose all distance vision// Not necessarily. If each eye merges its multiple faceted images into a single image, it might recover some of the resolution lost through each image being smaller. If so, your brain would still have two images (left and right eye) available to it, and should still be able to extract parallax (depth) information from them. |
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//We find it hard to imagine what it must be like to have totally spherical viewing,// We do. In fact, what is quite strange is that "behind you" isn't dark, or black or grey or white - it's simply not there. |
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Yes, but it's still strange. |
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Yes, but that would need glasses to convert IR or UV into visible light (and image it). Not impossible. |
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//If we're remapping the retina I'd devote some to
wider parts of the EM spectrum to detect e.g. IR or
UV.// |
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//We could then tell different sorts of grass apart and
know directly whether to wear sunscreen// |
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Actually, our eyes are bloody useless at objectively
working out how much light there is, even if we were
sensitive to UV we'd still get sun burn. I frequently
spend a long time looking at incredibly dim fluorescent
things down a microscope. I can look at two cells and
conclude that they're similar in brightness if they're
separated by enough distance that my eye has to move.
Pull up the same two cells on the EMCCD camera and
there can easily be a tenfold difference. The trouble is
your eye is constantly pulling tricks. Your iris will open
and close, I'm also convinced that your eye dwells on
brighter objects for less time, flicking to and from the
object at a different rate than dim objects. I'm sure
neuroscientiscts have it covered quite well, I may get
'round to reading it someday. Anyhow, light intensity
varies enormously and all the physical and neuronal
image processing keeps it within a narrow range, you'd
only know if the UV were particularly high if you could
see a reference alongside it, perhaps a door through to
a previous day. |
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That, [bs], is extremely true. Would you guess, for example, that the light levels on a sunny day at noon are about 100,000 times greater than the twilight immediately after sunset? Or 2,000 times brighter than a typical living room with the lights on, after dark? |
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Well, I would. Daylight is half a million fold brighter than
moonlight. Or 48 million % in tabloid units. |
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Ah yes. I was actually directing my question at [bigs]. And, for the record, you didn't guess, you knew. |
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//HDR, which is a technique for making every tone become closer to mid grey// |
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It's possible that I already have this installed in my retinas. Either that or I'm living in East Anglia. |
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" So, the experiment is to make eyeglasses which produce, on the retina, multiple small, identical images." |
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Not to spoil the party, and not WKTE either, but I had a pair of those in the seventies. Don't know who made them, and the earpieces had been broken off, but they were good for laughs at parties. |
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Interesting... If you're ever back in the 70's, grab me a pair. |
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It was just marginally tolerable the first time around, I try to avoid that decade whenever I have other options. I mean, the Led Zeppelin IV tour was awesome, but it was largely downhill from there. |
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These days I'm focused on being careful which timeline I'm in, what with President Rumsfeld's antics and all that nonsense. |
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I can make hours disappear just by drinking from my magic bottle. |
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