12-12-2005, 09:39 AM
Hi,
Now if you stare at the illusion for some time, the BV receptor cells get "overloaded" and exhausted because the color is especially chosen to stimulate them (and only them), and so that color component slowly fades away.
If you move your head/your eyes, the image of the violet dots "move" to other BV receptor cells in the eye which are still fresh, so the dots "reappear".
Another well-known optical trick is to stare at a red shape on a white background for some time, then look at a white background only. Your eyes will then "see" the same shape in the complementary color for some time because the YR cells are exhausted.
-Kylearan
Refrigerator,Dec 12 2005, 08:00 AM Wrote:That one with the moving dot is amazing. [...] Anyone know why this one works how it does?Your eyes have three different types of receptor cells for different colors, BV (blue-violet, ~460 nanometers), GY (green-yellow, ~530 nm), and YR (yellow-red, ~570 nm). Your perception of colors is made out of these three components (it's a bit more complicated in reality, but it suffices to explain this optical illusion).
Now if you stare at the illusion for some time, the BV receptor cells get "overloaded" and exhausted because the color is especially chosen to stimulate them (and only them), and so that color component slowly fades away.
If you move your head/your eyes, the image of the violet dots "move" to other BV receptor cells in the eye which are still fresh, so the dots "reappear".
Another well-known optical trick is to stare at a red shape on a white background for some time, then look at a white background only. Your eyes will then "see" the same shape in the complementary color for some time because the YR cells are exhausted.
-Kylearan
There are two kinds of fools. One says, "This is old, and therefore good." And one says, "This is new, and therefore better." - John Brunner, The Shockwave Rider