Identical images–click on image to see larger
This may be one of the oddest post I will ever make here and one of the hardest to present in a clear way.
Ever since I was very young, I have always wondered about our vision and how our brain translates the things we see. I can remember sitting in grade school and wondering if my classmates really see the same thing—if I could see through their eyes and translate that with my brain—as I do when I see RED, for instance. It wasn’t that I thought they didn’t see “RED” or relate “RED” to other colors as I did, but whether maybe their “Red” might be green or purple or something else if I saw what they saw but interpreted it with my brain. We know cultural norms can affect how beauty, for instance, is perceived but what about actual visual perception? Do we really “see” the same things or just interpret them the same?
I suppose that I saw this in one form, at least, when I was teaching at PNCA back in the 90’s. One of the students in my photo class would routinely bring in these photographs with the most incredible rendering of light within them. This “light” was incredible in the sense that I have probably only seen it a handful of times in my life—once that I can remember in one of my own photographs—other than in this person’s photographs. Everyone was pretty impressed (the photos themselves were alright, but that light!) A student who had been photographing for quite a while asked him “how” he got that light. Pondering that question, a more or less blank look came over the students face. I said “you have no idea, do you?” and he looked at me and said “no, I don’t”. For whatever reason he interpreted light in such a way that he “saw” things that most of us don’t. The question, really, might be whether he saw what he was seeing as exceptional in the way the rest of us did, or just as normal—and how did he see our rendering of light?
It might be a surprise to you that the two photos above are actually identical! Well, at least in the sense that they completely match when I isolate them and look at the one on the left with my left eye and the one on the right with my right eye (actually, they did until last Tuesday!). And it might be surprising that, in this case, they both look more like the one on the right than the one on the left. Let me explain the best I can, which is not going to be easy.
Like most of us will at some point, I have developed cataracts over the past decade or two or three… They’re the result, in my case, of spending so much of my life outdoors with much of that in the desert or on the water with no sunglasses or UV protection for my eyes. And, I suppose, age might also be a factor. Over the years, I have had friends who had developed them in their 30’s, so I guess I have been lucky that it has taken a bit longer. Apparently, certain types of eye injuries can help speed them along as well.
But it was about three years ago that they could no longer correct my eyes back to 20-20 with glasses. At the time, the Optometrist suggested that I was seeing things pretty yellow, given how the cataracts had progressed, and I said that I didn’t see things yellow at all, things seemed very clear to me and as “normal” as they ever did. He suggested that I just wasn’t recognizing it, as they were definitely pretty yellow and getting worse. It was also about that time that I had taken a Color Acuity Test and scored very high—a “6”, although not perfect (“0”) but with 99 being poor, I’d say my score was pretty good. (The test can be taken here: http://www.xrite.com/online-color-test-challenge.)
But things progressed over these last 3 years and although I knew there were some changes, I didn’t recognize them all. For instance, when I bought my Truck a year and a half ago, I couldn’t see the speedometer unless I turned on the dash lights. Not having that problem in my other truck or my wife’s car, I complained about it being a design flaw (it wasn’t!). I started to get rainbow halo’s around bright lights at night and driving at night became much less “fun”. I love to drive from predawn to after sunset! During the day, I needed to keep my sun visor down while driving to cut the “haze” caused by the bright sky. One of the worst side effects was that I could no longer read a book (a paper one) comfortably, as I couldn’t get the contrast to see clearly on a white page and it was worse with those fancy art books that don’t use pure black type! But color, that seemed totally normal to me.
Well, the fact is that I was halfway through cataract surgery when I created the side by side images above, last Monday. My left eye had been corrected the previous Thursday and on Tuesday, I was having the other eye done.
The first thing I noticed after that first eye was operated on was just how clear and BLUE everything was with the “fixed” eye—absolutely blue, not just in reference to the one not fixed yet. I wondered if the nodes in my eye were just so used to fighting the yellow that they needed to settle down. It wasn’t like seeing through a blue filter, just that neutral grays and whites just had a blue cast instead of being neutral. Actually, each day I have noticed that the extra “blue” had diminished a bit. But I was driving my wife nuts asking her to describe what she saw color-wise to gauge how my “new” eye was seeing—by last Monday it seemed to have all but lost the bluish bias but still a bit more so than what she described (she doesn’t have cataracts).
The image above, on the right, is one that I processed about a year ago through my cataracts. Looking at it with my now fixed eyes, it still looks pretty much as I felt I processed it, if not maybe just a tad “cooler”, but certainly acceptable as it is.
To create the one on the left, I blocked my left eye, the fixed one, so it could only see the left image and the right eye, which still had its cataract, so that it could only see the right image. Both images started out the same as the one on the right. The eyes certainly were seeing different renditions of the image. To equalize how I saw them with each eye, I made several Photoshop adjustment layers with masks to the left image to try to get the color, contrast and other visual effects to make what I saw with the left eye match what I saw with the right, unfixed, eye. Under this segregated procedure, these are extremely close except for a very small amount more clarity and contrast in the left image than what I was seeing with the right.
The odd thing was that as I was “creating” the one on the left, it didn’t look yellow at all, nor did the one on the right to my right eye. It wasn’t until I pulled away, allowing both eyes to see both images that I noticed the strong yellow in the one on the left. My brain seemed to still be “normalizing” what I was seeing color-wise, as I matched the two images as described above.
(I should note here that the same day that I created these images, I retook that color acuity test mentioned above. The “fixed” eye, which is my weaker one, scored a “9” while the uncorrected eye scored a “60”, which is a far cry from the “6” of just a few years ago!)*
But, when I wasn’t blocking either eye from seeing the image on the opposite side, I couldn’t get the right image to match the one on the left even by closing one eye and trying to look only at the image on its own side. The one on the right just looked “right” with the right eye and the one on the left yellow, with the left eye. The fixed eye did see the image on the right a bit cooler, and certainly sharper, but the right eye saw the right image pretty much as it appears except for those differences (there was a very slight yellow cast to the warmer nature of the image). The biggest color difference that I could notice was just that I could not see any of that rich yellow-green in the foliage in the center of the image on the far bank or in the reflections of the tree in the water.
When I again isolated the eyes to seeing only the image on the same side as the eye looking at that image, the yellow again disappears and the images normalize to each other—looking pretty much as the one on the right with those contrast and slightly warmer differences the “fixed” eye sees when looking at the right image.
I think what fascinates me most is just how the brain could find a way to interpret and normalize the color out of either eye, let alone the uncorrected color vision I have seen for the last couple of years. Certainly it wasn’t perfect, as I could see when comparing the fixed and non-fixed eyes, but in a reasonable range. I have gone back now and looked at the color images I have created over just this last year and although I might make some changes (warming some images up a bit), they are not garish, over saturated or too contrasty as I might have expected given the results indicated by the images above.
Anyway, I thought I might share this as I felt it really dovetailed well into some of the other posts here that have dealt with perception and reality and how the brain resolves all sorts of visual information. In this case, overcoming substantial color variance to give a “normal” view.
Please feel free to ask questions. I spent about an hour on the phone with a friend who saw these and heard the explanation and still was trying to get a grasp on what was going on. In fact, this was going to be posted last Tuesday but after the conversation, I wanted to see if I couldn’t make things more clear here. So, please ask questions if something isn’t clear and I will try to further clarify things. Thanks.
*4 weeks after my cataract surgery was completed for both eyes, I retook the color test and had a perfect score.