Andrea Mantegna, Camera degli Sposi ("The Oculus," 1473); Palazzo Ducale, MantuaScan © Mark Harden, used with permission
(noun) - Trompe l'oeil literally translates from French to mean "fools the eye." Hard to paint, the trompe l'oeil piece requires meticulous attention to detail on the part of the artist. Proper sizing and every detail, nuance of light and gradation of color must be skillfully incorporated in order to make the two-dimensional work appear to be three-dimensional.
Paintings of this genre have been around since Antiquity, though they fell into disuse during the "Dark Ages" It wasn't until the Italians (re)discovered linear perspective during the Renaissance that trompe l'oeil became popular for keeps. In the 21st-century, the term "Photo-Realism" would be equally applicable to this type of painting.