On his youtube channel, he recently asked a number of questions for sighted people. Though people have already provided him with answers, I also thought it would be a good idea to answer him as well.
Hello, I am Professor Preposterous. I am 33 years old, and have vision, albeit with somewhat severe nearsightedness. This means my vision is distorted past the range of my hands or so if I don't wear glasses.
How do you remember all those colors?
In general, I would say that there are millions of small variations on a small set of colors. A fashion designer might be able to tell the difference between "aquamarine" and "periwinkle," but to me both are just "blue." I can tell that they're a different shade of blue, but I don't see the point in differentiating further. To make a metaphor, I would compare colors to textures. A wooden object feels different to the touch than say, a plastic one, or a felt one, and if you pay a lot of attention, you might be able to tell if the wood is, say, pine, instead of spruce.
Color is actually due to the frequency of light that bounces off an object, light being an electromagnetic radiation that vision detects, the way that hearing detects compression waves in the air. There are seven basic ones:
- Red: 700 - 635 nm
- Orange: 635 - 590 nm
- Yellow: 590 - 560nm
- Green: 560 - 490nm
- Blue: 490 - 450nm
- Purple: 450 - 400nm
There's also black and white, which depend on if it is described with an additive color system (like a spotlight or a computer monitor) or a subtractive one (like paints). With additive systems, all the colors make white, and no colors make black. With a subtractive system, all the colors together makes black, and white has to be prepared separately. My computer monitor uses an additive system that can make basically every color there is from three: red, blue, and green.
Also, I would be very surprised if you were unable to provide me a similar level of detail about texture, or sound.
What's it like to be able to look at a room and know exactly where everything is? My god, that's genius.
Extremely orienting. Except that vision only shows you where everything is in a room if the room is sorted first -- vision is blocked by the first object with color that it encounters, so if something is behind something else, a sighted person can only see the thing in front. Sight also only works forward -- we see what's behind us about as well as you do, which is to say not at all. For what's behind us, we have to rely on hearing, or perhaps mirrors.
While in theory, vision's distance is unlimited, closer things provide more detail than further away things, any obstacle blocks further sight, and some of the things vision tells us are just plain outright lies. For example, the sky is not actually a thing -- there's air over our heads, but vision tells us that it's a large dome-shaped object at a large distance away, maybe 20 miles. Or the horizon, where the sky and the ground seems to touch if there are no large objects blocking it, which appears to be about 8 miles away, but moves with us if we move.
So, how come you stop and look at a hot chick? Guys at a red light, they'll stop traffic!
Vision provides a lot of information at once. Sometimes this is kind of distracting, especially with our lower brain, the one we got from lizards, hijacking everything else to think up pickup lines until we realize that we've been staring and have lost all chance of relating to her normally.
How do you remember what things look like? I mean, there are so many things. Like cars. How do you know the particular make of a car? Or vegetables? Fruit? Food?
Things don't really change all that often. If I were to hand a random object off my desk to you, you would probably recognize it instantly, because it feels the same as the other ones that you've encountered before. Let's say that I hand you an apple. The moment it touches your hand, you'd probably recognize it. Vision is the same -- seeing an object gives us the general shape, the color information, and hints at the texture of the object. Having seen similar objects before, we recognize them.
If you were somehow able to touch and feel every car extensively, every time you passed them, I think you would start to recognize particular models after about a month. Every car of a particular year, make, and model is shaped exactly the same. The color is different due to auto paint, but the texture is the same and the shape is the same. We recognize them because we've seen them before.
The same with food. Apples have the same general shape as other apples. Bananas have the same shape as other bananas.
Fashion blows my mind. I mean, you choose to wear something that looks good rather than feels good?
As someone in the applied sciences, fashion doesn't work well with me either. But people who wear things that look good usually like the attention that they get for doing so enough that they're willing to put up with a surprising amount of discomfort.
What's it like to go somewhere all by yourself?
On one hand, liberating. On the other, lonely. I was kind of surprised with the idea that you couldn't travel alone.
What about driving?
I learned to drive 17 years ago. When I first started, it was unbearable -- having to keep track of everything and do so many things at once took more brainpower than I had available. Over time, I got used to it as more and more things became habit and could be relegated to the unconscious, until I could drive and listen to the radio and muse about philosophy all at the same time. Cell phones are a bad idea though. And texting -- texting is just asking for trouble.
What's it like to walk around in the snow?
Snow doesn't support your weight and sinks when you step on it, with an annoying crunching sound. It's also super easy to get lost, the massive amount of reflected light gives sighted people a headache, it's wet, and it's cold. In my opinion snow can go die in a fire.
How do you not see something that happens right in front of your face?
Vision uses a huge amount of brainpower all by itself, so if you do it, your brain takes a lot of shortcuts. A sighted person can see something and not recognize it, or could be facing the wrong direction, because vision only works in front of you. Anything above or below, or behind, will just not be seen at all. If your sighted friend is facing the wrong way, his vision is just not going to help.
How do you lose sight of something? I mean, like you drop money on the floor and lose it?
Sight only works one layer deep, as it were. If the money goes under or behind something, sight will tell us that nothing's there. If money falls into the sofa, and we look at the sofa, we'll only see the sofa, not the money. Sometimes moving around can give us new information, like putting our head to the floor before looking at the sofa (oh hey, there's that quarter!)
How do you lose your car in a parking lot?
Unfortunately, cars are not all that unique. One particular make, year, and model of car, in a particular color, is as specific as it gets. There's at least three cars in any particular lot that exactly match the description of my car, so I'll walk to one and....this is somebody else's car. Damn it!
How do you miss the exit while driving? Wouldn't that be blatantly obvious?
With distractions, usually. You have to look at quite a lot of things very quickly, and the recognition step of vision sometimes comes too late due to the speed. Okay, avoid that car, check the rear view mirror, check the side, see the sign, avoid that other car, wait, that sign was indicating my exit. Damn!