Assessing higher-order visual functions: seeing beyond a flat earth.

Abstract

Vision is a sensory resource that enables the creation of an internal model for perceiving the external world. The act of seeing is much more than the mere process of light reflection on the retina. Higher-order visual areas play a fundamental role in the ability to see, providing visual perception and object recognition functions that are resources beyond the process of perceiving color, motion, and form. Disorders of higher visual abilities can be the result of a variety of etiologies. The bedside assessment of higher visual cortical functions provides clinicians with a valuable tool when suspecting individuals with these conditions.