Locus of the Stimulus to Visual Accommodation: Where in the World, or Where in the Eye.
Abstract
In two experiments, observers judged the apparent size of a collimated disk of light (a simulated moon) projected just above the horizon a real and virtual scenes by means of a stimulus presentation device, the 'moon machine.' As these judgments were registered, masks obscured various bands of the lower half of the visual field. Immediately following these judgments measurements of the observers' visual accommodation were made using a laser optometer. Results showed a strong correlation between mean apparent size and mean accommodation shift. Major conclusions were (1) viewing a virtual (collimated) image of a real scene is not the same as viewing the real scene, (2) for natural (real) scenes the retinal locus of scenic texture is the primary determinant of apparent size, whereas for virtual images it has a more reliable effect on visual accommodation, and (3) whatever the relationship between apparant size and visual accommodation is, their mean correlation is in excess of 0.90. These findings agree well with, and extend, those of Iavecchia, Iavecchia, and Roscoe (1978) and Simonelli and Roscoe (1979). (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1979
- Accession Number
- ADA094675
Entities
People
- Jan Christopher Hull
- Richard T. Gill
- Stanley N. Roscoe
Organizations
- New Mexico State University