According to brain expert John Medina, humans are remarkable at remembering visual information. Medina points out that if a student hears information, three days later he will only recall 10% of it. If an image is added, the recall level goes to 65%.
That is a strong argument for providing students with visual support for the concepts we want them to remember.
There are a variety of types of visual displays that support learning. Students should know exactly where these supports are located, be able to see them, and use them to support their learning.