Colors Out of Space

Ummm, it totally looks like she has two gray eyes.

fnerg like fnarf?

anyway, are you colorblind? I ask only because I truly "see" one blue eyes. I had to copy the image into Paint and delete the red portions before I could believe it is grey.

Ok, I call scientific fraud on this. There is little sense to this claim and if anything they're saying you're color blind, which you aren't.

There's always one who feels the need to let everyone know that optical illusions can't fool them.

It pans out, photoshop says it's grey....

This is not an optical illusion, her left eye actually is blue. Or to be more rigorous, the image depicts exactly the same pixels that would be depicted if the left eye would actually be blue and the red filter in the left half of the image would cover the entire left half of the image, as implied by the image itself.

Or to put it another way, if I shot an actual image of an actual house with an aggressive red filter and I found some random blue object (say, a watering can) to be rendered as gray in the final image, could I legitimately claim that I produced an amazing optical illusion because the watering can appears blue but is in fact gray? No, I could not, because my "grey" watering can was in fact blue, and my photo was not an optical illusion. Therefore this is not an optical illusion either, because the left eye is actually blue.

Bogus hoax - copy the image into any editor, cut the left eye and move it next to the right eye - it's blue. Illusions are real, but this is baloney. How about a fact check before posting something this obvious, Neatorama?

Yeahasif, I don't know what you did, but to see that they are both grey, you have to take the border and pupil out. They eyes are both gray. I tested it.

I copied the image into Paint Shop Pro, then cut out the eye on the left (the "blue" one) and placed it next to the one on the right. I then zoomed in so I could see the pixels. The eye on the left does in fact contain some greenish/bluish pixels, whereas the eye on the right is more uniformly gray.

So no, this isn't just a case of me trying to admit that I'm not fooled by optical illusions.

Yeah, I did the same thing as Popcorn and the eye on the left def has some green/blue in the coloring.
The optical illusion still kind of worked though b/c the grey did start to show more once I got rid of all of the red.

I checked as well in paint. There is indeed an extremely faint trace of blue/green, but imo not enough to explain the effect. Probably due to the jpg compression. They should have stuck with a bitmap or something else that is not lossy.

Anyway, the effect is very real indeed, there are a lot of similar examples to be found on the net (or in the original article).

Feodor, you don't seem to have grasped the concept of optical illusions. The left eye in the picture "actually" (as in, the pixels that are displayed by your computer screen) is grey. Your brain then interprets the picture as having a filter placed over it, and therefore "sees" the eye as being blue.

So.. pixels -> grey; what you see -> blue. Hence: optical illusion.

By the way, to all the left-eye-greyness-deniers, the left eye is grey. It just is, you know it, everybody who can use MS paint knows it, and trying to find bluish pixels is missing the point.

@Seban: according to the dictionary, an illusion is "something that deceives by producing a false or misleading impression of reality". In my watering can example, reality is the real color of the watering can. And since the real color of the watering can is blue, there would be no illusion -- there's no deceiving going on when something blue is being perceived as blue.

An optical illusion is when you're deceived into thinking that two lines have different lengths when in fact they have the same length; or when you're deceived into thinking something is moving when in reality it's static -- but when you're being "deceived" into thinking that something is blue when in reality it actually is blue... not much of an illusion.

Also, the eye is indeed a bit greenish, which is indicative of the fact that whoever created this image probably did exactly what I described in my watering can example above: I guess they actually painted the eye blue, and then fiddled with a red filter until they reached the point where the filter approximated grey for the eye. If the "illusion" had been constructed cleanly then there would've been no color spill (as proper, geometrical illusions are constructed, like the other three in the gallery mentioned in the post).

I replaced the eye on the red side with the eye from the right side and the illusion worked just as well.

A very common kind of color-based illusion. If you find something wrong with this one, there are thousands more.

For a complete explanation pick up one of these books (they all explain it): The Engine of Reason The Seat of the Soul by Paul Churchland, Brain-Wise by Pat Churchland, The Astonishing Hypothesis: The Scientific Search for the Soul by Francis Crick, The Quest for Consciousness: A Neurobiological Approach by Christoph Koch.

There is also a video called The Neuroscience of Nothing which explains contrast luminosity, but the simplest way of explaining any of this kind of thing is to point to the completely relative nature of everything that the human mind produces. Color is not a concrete empiric quality, but is a relative continuum generated by your mind. Just like... your idea of your self and your idea of an actually existing objective world.

So here is a great article from "Scholarpedia: The Peer-Reviewed Open Access Encyclopedia" this article on color-vision including the opponency process is written by Karen K. DeValois and Michael A. Webster.

http://www.scholarpedia.org/article/Color_vision