The estimation of eyeball protrusion from the bony orbit has traditionally relied upon Wolff's theory (1976) that the cornea will be tangental to a line taken from the superior to the inferior orbital margin. This study tested this theory by taking measurements from MRI cranial images of 78 eyes of white adult subjects. Orbital depth had a significant negative linear correlation with eyeball protrusion, and protrusion of the eyeball was determined by the following standard: eyeball protrusion = 18.3 — (0.4 x orbit depth). Current eyeball position determination was shown to be as much as 3.9 mm too deep in the socket, and a practical application of this result to facial reconstruction is discussed.