Jesus optical illusion Answered

This is also my favorite illusion. I found this vid from the best of YouTube podcast back when it was cool. It's because your eyes see the negative of the colors when you look away (or in this case, another object appears) from the picture. Same deal with the illusion the OP made.

It didn't "appear as color until I looked away"; I mean, I saw the color, but within 2 seconds my eyes readjusted and it faded to b&w again. :-(

It stays as long as I don't blink. If I look away, the color goes away. Maybe your eyes are wired backwards or something...

Either that or they recover quickly or possibly get "tired" more quickly :-)

That is pretty cool. That's a very clever combination of two optical responses. Nice.

that's pretty cool side note, I hate optical illusions that have a scary something and go ahhhhhhh !!!!!

Retinal impression. It is the reason you see spots after you close your eyes after being in bright lights. The neurons continue to fire and you "see" what is not really there (most ghost sitings are because of this, the reason they are seen in "the dark" :-)

Plus there is a reflex whereby, if one set of nerve-endings has been firing for some time, as soon as they are allowed to relax, the neighbouring nerves fire for a few moments.

It's why you see a negative image of what you stared at, and it works for colours as well (stare at a red dot, blink at the wall and you will see a green after-image, and vice-versa).

Stare at the dot in the centre of this odd-looking American flag for at least 30 seconds and then blink away at a plain white surface.

I guess thats how the video of the castle works as well. I never knew exactly why it did that, and just dismissed it as voodoo magic.