A few times in my life, usually after keeping my eyes shut for a while under bright sunlight (like lying on the beach or meditating in a field), upon opening them my entire vision is in grayscale – no colors at all. I can maintain it for a good half a minute or so, but if I move my eyes even the slightest bit, the colors start to return.
What causes this phenomenon? Even if it’s purely imaginary (or mental) and not physical, the effect is so strong and so long-lasting that it’s hard to write off as a temporary madness…
My brain is trying to regurgitate 30-year-old memories from freshman physiology here, so this may be worth about as much as you pay for it, but isn’t rhodopsin continually degraded and enzymatically regenerated? IOW, if you use up all you have, don’t you have to wait a few seconds for more to be made?
I have never experienced or heard of such a phenomenon, but one thing I do know: There is no way you can, by sheer will, keep from moving your eyes “even the slightest bit” for a full half minute. If, by some miracle, you did, you would not just fail to see colors, you would (after well under a second) cease to see anything at all.
I wouldn’t rule this out as a purely psychosomatic thing. The brain has an impressive ability to see what it wants to.
If there is a physiological cause, the only thing I can suggest is that the low-light receptors in our eyes are primarily black and white. If you’ve had your eyes closed, then those may have been generating most of the signals going to your brain and maybe you have a weird quirk where the brain keeps getting most of its input from these low-light receptors. It’s only after consciously moving your eyes that the brain starts to incorporate the rest of the visual input.
In bright light, bright enough to see color properly, the rod cells (“low-light receptors”) won’t work at all. They are all maxed out, with their response at ceiling (and you need differential responses from nearby cells to actually see anything).
dracoi, is it possible that what is really happening is that you are blinking open your eyes to a bright scene just very briefly, then closing them again and experiencing a positive afterimage? This might also explain why you think you are able to keep you eyes still for so long in these circumstances. Positive afterimages are actually very common in such circumstances, and, unlike the better known and better understood negative afterimages, they retain the same pattern of light and dark as the original scene, rather than it opposite. Often they are colored the same as the original scene too, but I think it is possible that uncolored ones may also sometimes occur. Positive afterimages (of which there may be several varieties) are not too well understood, scientifically, and it is hard to find good information about them (especially on line), but Google just turned up this paper for me [PDF] which suggests that vivid rod-based positive afterimages are possible, and are vivid enough to be confused with the original stimulus itself. If they are entirely rod based, they would presumably be in monochrome.
Had a experience of deep depression many years ago when I saw only in septa colors, this was over a few days. I don’t know if is related to what you experienced. Also FWIW food had no taste.
Your peripheral vision has remarkably poor color perception. Your brain does a lot of work filling in the gaps. If you open your eyes and keep your eyes focused on one spot, your brain might not have enough information to give strong chrominance information but would still have good luminance information, presenting you with a near-greyscale world.
Yes, but the peripheral retina has very poor spatial resolution too. (The truth is, that about all it is good for is detecting movements and ill defined obstacles.) So if (big if) you could keep your eyes still enough under these circumstances, you would not only fail to see color in most of your visual field, you would fail to see much of anything at all.
I suppose, though, that it is possible that that is what the OP is really experiencing: not a normally detailed but monochrome world, but a world that contains neither color nor much else, except perhaps at the very centre of the visual field. I can see how that might happen if you were able to keep your eyes relatively still for a period after opening them. (Most people will not do that, and would probably find it very difficult, but perhaps the OP is exceptional in this regard.) There is some evidence to suggest that even foveal color vision, depends on eye movements.
Hmm. Interesting theories! I wish I could give you guys better information, but I guess it was an entirely subjective experience and I can’t really prove to you what I saw.
That said:
I really doubt I’m exceptional in any way when it comes to vision.
I didn’t know that eyes involuntarily move around all the time. It felt like I was staring at one spot.
There was enough detail in the image that I could still make out features as they normally would appear. I remember opening my eyes, thinking “Huh? Where did all the color go? Am I imagining this?” And then, afraid of making the effect go away, I kept my eyes forced open and trained on one spot (like a staring contest) for as long as I could while focusing my attention on different spots of the image, trying my best not to actually move my eyes. I remember thinking “What the hell… this can’t be happening. I don’t understand. That grass is supposed to be green. That hay bale is supposed to be yellow. The sky… isn’t even blue.” Then, when I felt like I had exhausted what I was able to make out without actually re-focusing my vision, I blinked a few times and the effect immediately went away and all the color came back. There was a very distinct moment when that happened, like “Yup, so THERE’s all the color.”
This has only ever happened twice in my life (I’m 29), the first time for about 30 seconds when I was completely entranced by it and another time for about 5-6 seconds.
I can definitely believe that it’s entirely psychosomatic, I just wish I knew how to make it happen more often. It’s COOL.
I tried this just today. I sat in the Sun with my eyes closed for a while. When I opened them, I could still see color. My sight contrast was reduced because my eyes were looking at my bright inner eyelids, but there was still color.
It’s not something I can recreate at will either. I was hoping someone else might’ve experienced it at some point in their lives, but oh well. I guess I just imagined it.