Mona Lisa's smile appears and disappears as we alternate between peripheral and central vision.
If your eyesight is good, you probably think everything you see is always in sharp focus, like a photograph; this isn't the case.
You know that dictionary game in which someone chooses an unusual word and everyone makes up a definition for it. Well, I’ve got a good word for you. Strabismus. Learn more on this Moment of Science.
Learn about peripheral vision and color on this Moment of Science.
What's the deal with Mona Lisa's smile? Find out on this Moment of Science.