mrdan86 wrote:
Where are you quoting from @philip_pj@@?
I'm right handed and left eye'd. I've thought about training my right eye but it really only matters on mechanical rangefinders when trying to get the eye fully seated on the eye cup to be able to see the entire viewfinder, and even still doesn't feel like that much of a hindrance.
I am not sure where Phillip got his quotes, but they are oversimplified accounts of what happens in the brain and misleading in several ways.
For example, neural signals don't go directly from the retina to the visual cortex, which is in the very back of the brain. They first past through the thalamus with is deep in the center of the brain and early processing of the neural signal begins there before it reaches the visual cortex. Importantly, signals from the left side of each eye cross over here and continue on to the right side of the visual cortex and the reverse happens with the right side of each eye. So the signals for both eyes are split in this way. As you might know most of the muscles in the right side of the body are controlled by the left side of the brain and most of the muscles in the left side of the body are controlled by the right side of the brain.
So let's say you are right eye dominant like I am, if the brain gives prominence to the information from my right eye this means that it gives prominence to the information from my right eye for what I see on both the right side of what I am seeing and the left side of what I am seeing over what I am seeing in my left eye on both the right side of what I am seeing and the left side of what I am seeing. So both the right side of what you are seeing *and* the left side of what you are seeing is relying more on your right eye. How does the brain do that? The answer probably lies in that the brain is very flexible in processing information and quite good at using multiple mechanisms to optimize clarity in vision. Eye dominance for many of us may well just be that optimizing of optical clarity and relying on the eye that provides a better signal at least some of the time. Our vision is redundant, we have two eyes and with extensive overlap in processing of visual information, but our brains are also good at using visual information that leads to clarity in what we see. If anyone has progressive glasses like I do with zones that optimize close vision in some areas of the visual field and far vision in others you know that the brain adapts to these lenses and you "just see," close stuff and far stuff without consciously trying to use one zone or the other. I think it is likely something similar occurs for eye dominance in our vision. If one eye is better at some aspects of vision than the other eye, then the brain will rely on that signal more when processing information. If one eye has better vision than the other eye, then it would make sense for the brain rely on the information from that eye more, but it could be complex so that one eye is better with close distances and one eye better with far distances, but the brain can likely optimize for that too just like it does for progressive lenses. Note this process is dynamic and is not fixed. If people's vision changes, for example when they have cataract surgery or even if they get new glasses, the dominance of the use of information from one eye vs. the other can also change as the part of the visual field relied upon changes when someone gets progressive glasses.
Finally the bit about 80% of the brain being used for visual processing is highly misleading. The whole brain is used for the processing of almost everything and in fact even when we are sitting silently with our eyes closed our brains are very active and processing lots of information. What percentage of all the activity is due to any one stimulus, vision, hearing, touch, etc really con't be determined in any meaningful way. The brain does get very active when it processes visual stuff, but it gets very active in slightly different ways when it processes a whole bunch of other types of information as well. Understanding brain activity begins by understanding that processing information in the brain is complex and simple percentages like that never do justice to the complexity of what is going on.
Oh, by the way I am not a neuroscientist, but I play one in front of college classes when I teach introductory psychology and what I am sharing here is pretty much straight out of those lectures. My PhD is in social psychology which only touches upon brain activity where it bumps up against neuroscience. There is a subfield of social psychology called social neuroscience and one of my colleagues is in that subfield. It just so happens that today I am working on a paper with that colleague and a student we jointly supervise. That works makes it abundantly clear to me how much I don't know about the brain, which is almost everything and even my colleagues that know tremendously more than I do acknowledge there is so much that they don't know about the brain. Nevertheless the little bit of information that is known about the brain is enough to know that authoritative statements like the ones in Phillip's post are gross oversimplifications and more misleading than helpful. I suspect they come from AI. AI is still really bad at stuff like that and for a fundamental reason. AI is still really bad at acknowledging what it does not know. AI just never says, "I don't really know. We might know a lot more in 50 or 100 years, but right now it is too complex for me to understand." Instead it offer simplistic answers that are not helpful. That is what I think happened here.
Steve Spencer wrote:
So let's say you are right eye dominant like I am, if the brain gives prominence to the information from my right eye this means that it gives prominence to the information from my right eye for what I see on both the right side of what I am seeing and the left side of what I am seeing over what I am seeing in my left eye on both the right side of what I am seeing and the left side of what I am seeing. So both the right side of what you are seeing *and* the left side of what you are seeing is relying more on your right eye. How does the brain do that? The answer probably lies in that the brain is very flexible in processing information and quite good at using multiple mechanisms to optimize clarity in vision. Eye dominance for many of us may well just be that optimizing of optical clarity and relying on the eye that provides a better signal at least some of the time. Our vision is redundant, we have two eyes and with extensive overlap in processing of visual information, but our brains are also good at using visual information that leads to clarity in what we see. If anyone has progressive glasses like I do with zones that optimize close vision in some areas of the visual field and far vision in others you know that the brain adapts to these lenses and you "just see," close stuff and far stuff without consciously trying to use one zone or the other. I think it is likely something similar occurs for eye dominance in our vision. If one eye is better at some aspects of vision than the other eye, then the brain will rely on that signal more when processing information. If one eye has better vision than the other eye, then it would make sense for the brain rely on the information from that eye more, but it could be complex so that one eye is better with close distances and one eye better with far distances, but the brain can likely optimize for that too just like it does for progressive lenses. Note this process is dynamic and is not fixed. If people's vision changes, for example when they have cataract surgery or even if they get new glasses, the dominance of the use of information from one eye vs. the other can also change as the part of the visual field relied upon changes when someone gets progressive glasses.
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It seems like the brain does optimize clarity. I'm left eye dominant, but when I had a temporary issue with the retina in one eye where part of the vision in that eye became darker (1-2 stops in photo terms), my right eye became dominant. When the condition cleared up, my left eye became dominant again.
