Luna and her family are at the beach, even their grandparents have joined them. When Grandpa wants to get a better look at a photo, he takes his glasses off, but Grandma has to put hers on. And it gets Luna wondering... why does Grandpa have to take his glasses off but Grandma needs to put hers on? Why do some people need glasses and others don't? How do glasses work? Learning Objectives: Understand that for each type of visual deficiency, there are specific glasses and there are people that don't need glasses at all.