My four-year-old daughter's pre-school visited a nursing home. When they got back to class, they teacher asked them to describe what old people look like. Here are their answers.
Q: What do old people look like?
A: Very old. Their stomach is very big. They have a wheelchair. They look like they can't walk.
Here are two other Flickr galleries of my kids' class drawings, containing similar sentiments: Preschoolers' feelings, What happens to people when they get old?