Background

"The Eclipse" is a very old optical illusion. It was originally used to test blues for the purest cyan. As a visual deception however, it has won numerous awards, including several appearances on Amos Storkey's optical illusion page.

What is the optical illusion supposed to show?

The "Eclipse" (or "The Eclipse of Mars") illusion is supposed to show a luminous glow around a red circle, which is presumably representing the planet "Mars". However, in our version, along with the classic 'red' stimulus, we also provide 'green', 'dark blue' and 'cyan' images (stimuli) to see what observations you can make.

How can I make the illusion occur?

Click here (or on the thumbnail image next to "Category: Optical Illusions") and stare at the large red circle that appears. An outline will begin to appear around the circle, but do not stop staring. Continue to stare for about another 30 seconds - keeping your head reasonably still and trying not to blink - and then slowly move backwards (without affecting your height) and see the "Eclipse"!

Images

Below are three alternate versions of the "Eclipse". Click on each for an enlarged view of the optical illusion:

How does it work?

The Eclipse illusion is based on after-image illusions. When you stare at this particular colours, if you were to close your eyes, or look at a white wall, you would see an exact opposite colour of what you were originally viewing. By moving your head backwards, you increase the size of this after-image, thus creating the illusion of an eclipse.