Department of Optometry and Visual Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.

Corresponding Author: Andrews Nartey, Department of Optometry and Visual Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana, Tel: +233 50 137 4148; E-Mail: [email protected]

Received Date: 16 Mar 2017   
Accepted Date: 12 Apr 2017  
Published Date: 13 Apr 2017

Copyright © 2017 Osei-Afriyie G

Citation: Osei-Afriyie G, Nartey A, Kumah DB, Bonsu K, et al. (2017). Influence of Viewing Distance and Illumination on Projection Screen Visual Performance. Mathews J Ophthalmol. 2(2): 016.

Projectors and projection screens have become basic and indispensable teaching aids in modern societies, and in particular, tertiary institutions. This study sought to investigate the effect of viewing distance and illumination on visual performance whilst working from a projection screen. The study, which was conducted in two lecture rooms, involved 60 participants who engaged in two different visual tasks: a proofreading task and a film-watching task. The identification rate (IR) and attention rate (AR) for the proofreading and film-watching task were collected respectively. Viewing distances of 3 m, 6 m and 9 m and illumination of 300 lux (low) and 1600 lux (high) were the independent variables. Statistical Package for Social Sciences version 23 was used to analyse the data and the level of significance was set at a p-value of 5%. The effect of illumination on proofreading performance (p = 0.026) and on film-watching performance (p = 0.004) was of statistical significance. Mean statistics showed that viewing distance affected the visual performance, with mean identification rate being inversely proportional to viewing distance and illumination. Mean attention rate peaked at 6m and was also optimum in low illumination. However, there was no significant effect of viewing distance on proofreading performance (p = 0.684) and film-watching performance (p = 0.370). Thus, to attain maximum visual performance whilst using projection screens, illumination must be considered.

Viewing Distance; Illumination; Projection Screen; Visual Performance.