Does the moon change size? It sure looks like it! Two optical illusions are suggested as an explanation: Ebbinghaus and Ponzo. However, there are problems with both of these. Convergence micropsia may answer the question, but many scientists disagree. The video explores the question, but ends with no conclusive answer. You could show this little film when examining optical illusions in a light or eye unit, or as an enhancement to a lesson on the moon. Questions for comprehension and discussion are provided if you sign in for a free membership on the publisher's website.