Experiments critical of the effectiveness of variables of optical texture in evoking accurate judgments of slant are shown to be inappropriate, inadequate, or deficient. Experiments supporting linear perspective as a stimulus for slant are evaluated. The contention that perceived slant is a function primarily of linear perspective is shown to be oversimplified and hardly adequate to cope with the facts. Some aspects of Flock's theoretical model specifying optical stimuli for slant are discussed.(24 ref.)(PsycINFO Database Record (c) 2016 APA, all rights reserved)