It is proposed that visual literacy be defined as the ability to understand (read) and use (write) images and to think and learn in terms of images. This definition includes three basic principles: (1) visuals are a language and thus analogous to verbal language; (2) a visually literate person should be able to understand (read) images and use (write) visual language; and (3) a visually literate person should be able to process information visually in order to think visually. Noting that the third principle is supported by research findings, it is argued that teaching students to be visually literate involves sharing mental strategies or processes that use mental imagery, visualization, mnemonics, dual coding, and symbolic systems to store information, interpret and develop ideas, solve problems, and process information. It is suggested that it is time to take another step toward the management of information by teaching people strategies and methods for thinking visually. An extensive bibliography is appended. (Author/MER)