Visual angle is a dimension used to indicate the size of visual stimuli subtended at the eye without having to specify actual stimulus size or distance and is used to specify intraocular dimensions.
Visual angle predicts the amount of space that an image will subtend on the retina and describes the relative location of separate retinal images. It is also used to specify the size of spatial frequency gratings. It is formed by incoming light rays at the nodal point of the eye and is dependent on the size of the stimulus, its distance from the observer, and whether or not it is viewed in the frontal plane. In a simplified model, visual angle is formed from the light rays from two points (in height, width, or depth) of a viewed object as they enter the eye and is proportional to the angle projected onto the retina. The size of the subtended image is thus determined by the visual angle. An object viewed from different distances will have...
References and Readings
- De Valois, R. L., & De Valois, K. K. (1988). Spatial vision. New York: Oxford University Press.Google Scholar