Have students consider your visual examples and decide which ones look deep and why. Overlapping objects show which is farther. Objects have less detail as they get farther away.
Close objects are brightest and sharpest.
Objects in the distance appear pale and washed out. Cool colors may appear farther away. Introduce the Renaissance and the development of linear perspective. Many artists and cultures have not valued the realistic portrayal of space. You could discuss why some artists have developed a realistic style for portraying depth while others have not.