Yellow Spot In Eye Vision

Eye Tests That Look Like Magic

blind spots. human eyes have a blind spot when the optic nerve exits the back in the eye. this area has no light receptors because the nerve is in the way you can find your blind spot with this test. look at the red cross on the left with your right eye closing your left eye, move your head slowly closer and further away quot;So weirdquot; at a certain distance the blue dot on the right will disappear

pause if you need to, you've just found your blind spot After images, stare at the white dot in the center of the image and try not to blink. your eyes have three types of cones or color receptors red, green and blue. after images appear when you stare at a particular color for too long and those color receptors get tired. so when you suddenly switch to looking at a black and white image

those tired receptors aren't working as well this leaves an afterimage of the reverse colors. See your veins. blood vessels and veins feed the photosensitive cells in your eye to keep them alive these blood vessels cast shadows on your retina here's how you can see those veins. poke a small hole in a post it note or piece of paper hold that against a bright white background like your computer screen

look to the hole while shaking the postit slightly you should see a shadowy network online sort of like the veins a leaf these are the veins in your eye quot;Oh, wowquot; Gross. dominant eyes most people have a dominant eyes, I'm meaning that one eye gives more priority information than the other eighty percent of people are right eye dominant see which is your dominant eye. make a triangle between your thumbs and

forefingers With both eyes open, look at an object several feet away Center the object inside the triangle, close one eye and then the other. your dominant eye will look like this and your nondominant eye it will look like this. it's almost visionary. see what I did there.

Is Your Red The Same as My Red

Hey, Vsauce. Michael here. This appears blue. This appears yellow.And this appears green. Those of us with normal color vision can probably agree.But that doesn't change the fact that color is an illusion. Color, as we know it, does not exist in theoutside world, beyond us, like gravity or protons do. Instead, color is created insideour heads. Our brains convert a certain range of the electromagnetic spectrum into color.I can measure the wavelength of radiation, but I can't measure or observethe experience of a color inside your mind. So, how do I know that when you and me lookat a strawberry, and, in my brain, this perception

occurs, which I call quot;red,quot; that, in yourbrain, a perception like this doesn't occur, which you have, of course, also learned tocall red. We both call it red. We communicate effectively and walk away, never knowing justhow different each of our internal experiences really were. Of course, we already know that not everybodysees color in exactly the same way. One example would be color blindness. But we can diagnoseand discuss these differences because people with the conditions fail to see things that most of us can. Conceivably though, there could be ways ofseeing that we use that cause colors to look

differently in different people's minds, withoutaltering their performances on any tests we could come up with. Of course, if that were the case, wouldn'tsome people think other colors look better than othersé Or that some colors were morecomplimentary of othersé Well, yeah, but doesn't that already happené This matters because it shows how fundamentally,in terms of our perceptions, we are all alone in our minds. Let's say I met an alien from a far away solarsystem who, lucky enough, could speak English,

but had never, and could never, feel pain.I could explain to the alien that pain is sent through A delta and C fibers to the spinalchord. The alien could learn every single cell and pathway and process and chemicalinvolved in the feeling of pain. The alien could pass a biology exam about pain andbelieve that pain, to us, generally is a bad thing. But no matter how much he learned, the alienwould never actually feel pain. Philosophers call these ineffable, raw feelings quot;Qualia.quot;And our inability to connect physical phenomenon to these raw feelings, our inability to explainand share our own internal qualia is known

as the quot;Explanatory Gap.quot; This gap is confrontedwhen describing color to someone who's been blind their entire life. Tommy Edison has never been able to see.He has a YouTube channel where he describes what being blind is like. It's an amazing channel.In one tutorial he talks about colors and how strange and foreign of a concept it seemsto him. Sighted people try to explain, for instance, that red is quot;hot,quot; and blue is quot;cold.quot;But to someone who has never seen a single color, that just seems weird. And, as he explains,it has never caused him to finally see a color. Some philosophers, like Daniel Dennett, arguethat qualia may be private and ineffable simply

because of a failure of our own language,not because they are necessarily always going to be impossible to share. There may be an alien race that communicatesin a language that causes colors to appear in your brain without your retina having tobe involved at all. Or without you having to have ever needed to actually see the coloryourself. Perhaps, even in English, he says, given millions and billions of words usedin just the right way, it may be possible to adequately describe a color such that ablind person could see it for the first time. Or you could figure out that, onceandforall,yes or no, in fact, you and your friend

Leave a Reply