An optical illusion on colors, take note of the colour of background A and background B, the Grey color of both A and B appears to be different. One slightly darker than the other, or so it seems to be. Is it really different in terms of tone? The truth is, both A and B are of the same color, take a look at the Grey strip that runs across both the checkerboard boxes. Our mind is playing tricks with us.
This optical illusion also emphasises the significance of relativity when attempting to measure things – and the effects of perspective, in this case light and shadow. What we see changes according to how we are seeing it. Perspective and relativity determine values. Very few things are absolute. Most things are relative and depend on one’s viewpoint and the context in which they exist.