I can’t believe we still haven’t discussed one of the most common optical illusions that we see almost each day. I’m talking about Moon Optical Illusion. The short intro would go something like this: The Moon illusion is an optical illusion in which the Moon appears larger near the horizon than it does while higher up in the sky. This illusion also occurs with the sun and star constellations. It has been known since ancient times, and recorded by numerous different cultures. There have been numerous tries to figure out why this phenomenon occurs (check Wikipedia), and the closest one in my belief would be “Relative Sizes” explanation – something we explained in the Ebbinghaus article and the Ponzo Collection. What do you think about it? What is your explanation? Have you noticed this illusion as well?