The term dysmorphopsia has been proposed for impaired vision for shapes, a visual recognition defect in which visual acuity, color vision, tactile recognition and visually-guided reaching movements are intact. These phenomena have been associated with bilateral lateral occipital cortical damage (e.g., after carbon monoxide poisoning) and are thought to reflect a selective loss of the magnocellular visual pathway. Whether this condition is an agnosia for shape or visual form, or a perceptual problem ("pseudoagnosia"), remains a subject of debate and the term dysmorphopsia has been suggested as a compromise between the different strands of thought.
Milner AD, Perrett DI, Johnston RS, et al. Perception and action in "visual form agnosia." Brain 1991; 114: 405-428