Accession Number : ADA185861

Title :   Target Size and Luminance Effects on Accommodation and Vergence.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH

Personal Author(s) : McLin, Leon Norse, Jr

PDF Url : ADA185861

Report Date : Jan 1987

Pagination or Media Count : 187

Abstract : This investigation, using Schor's (Schor and Kotulak 1986) dual interaction model of accommodation and vergence sought to determine how three different stimuli, namely dynamic size changes, voluntary effort, and luminance changes might influence accommodation and vergence. The mutual independence of the accommodative convergence and convergence accommodation crosslinks are primary features of this model. The AC/A and CA/C ratios were used as a tool to determine whether changing size or voluntary efforts was primarily influencing accommodation or vergence. Another main feature of this model is the separate tonic adapters for vergence and accommodation that occur after the crosslinks. Schor et al. (1986) found that tonic aftereffects of accommodation are masked in darkness. We investigated the effect of different luminance levels on these tonic aftereffects. In chapter 2, changing size was found to produce changes in both accommodation adn vergence adn these changes occur in a ratio like the AC/A ratio rather than the CA/C ratio. In chapter 3, voluntary effort is shown to produce changes in accommodation and vergence in proportions of an AC/A ratio rather than a CA/C ratio. In chapter 4, accommodative aftereffects were shown to be masked in scotopic luminance levels and partially masked at mesopic luminance levels when the accommodative loop was opened with a pinhole.

Descriptors :   *ADAPTATION(PHYSIOLOGY), *VISION, ADAPTERS, DARKNESS, DYNAMICS, INTERACTIONS, LUMINANCE, MODELS, RATIOS, SIZES(DIMENSIONS), STIMULI, TARGETS, CONVERGENCE, RESPONSE(BIOLOGY), OPTOMETERS, THESES

Subject Categories : Anatomy and Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE