Accession Number : AD0738940

Title :   Disability Glare and Contrast on the Snellen Eye Chart in General Practice,

Corporate Author : ARMY MATERIEL COMMAND TEXARKANA TEX INTERN TRAINING CENTER

Personal Author(s) : Patterson,Charles Tillman , III

Report Date : MAY 1969

Pagination or Media Count : 61

Abstract : Seven male graduate students, that required no visual correction, were tested at six General Practitioners offices composed of three levels of disability glare (technically-equivalent foot lamberts): G1 below 0.18; G2 above 0.18 but below 0.45; and G3 above 0.45; and two levels of contrast fraction (between background and character): G1 below 0.940 and G2 above 0.940. The Snellen test scores were recorded by indicating the characters within a particular string of characters incorrectly identified by the test subject. Precise scores were determined by interpolating between the character strings based on the inverse of Sheard's relative acuity of the individual characters. A randomized complete blocks design (2X3X7) with repeated measurements was selected for treatment by analysis of variance. The Newman-Keuls statistic was utilized for the interpretation of the interaction term. The results indicates (a) that there was a variance between treatments (b) that contrast was insignificant (c) that disability glare is significant (d) that disability glare and contrast have a significant interaction in the higher ranges of disability glare. (Author)

Descriptors :   (*VISUAL ACUITY, *TEST METHODS), VISUAL PERCEPTION, OPHTHALMOLOGY, VISION, MEASUREMENT

Subject Categories : Personnel Management and Labor Relations

Distribution Statement : APPROVED FOR PUBLIC RELEASE