A work test for quantitative study of visual performance and fatigue

Abstract

The authors have developed a test for the study of visual performance and fatigue. The visual task consists in the recognition of letters presented on a belt moving behind a narrow slit. Difficulty of the task is adjusted by using different letter sizes, different speeds, or different contrast. In a series of tests consisting of 200 letters presented over a 2 hour work period, the effect of varying intensities of illumination (2, 5, and 50 f. c.) was reflected in (1) higher general level of performance, (2) smaller fatigue decrement in output, and (3) smaller inter-individual variability. The authors believe that the test satisfies the following requisites of a good visual performance test: (1) well standardized work task; (2) possibility of easy quantitative evaluation; (3) clearcut relationship to fundamental visual functions; (4) elimination of auxiliary functions, such as manual skill or verbal intelligence; (5) elimination, as far as possible, of uncontrolled factors affecting performance, particularly continued training; (6) practical applicability of results; (7) possibility to vary critical factors of performance. 9 references. (PsycInfo Database Record (c) 2025 APA, all rights reserved)