Visual Impairment, Adaptation Luminance, and Glare: An Empirical Investigation

Abstract

Visually impaired people primarily rely on their remaining vision. Unfavorable lighting conditions can further hamper this remaining vision. In this context, the present contribution mainly focuses on the evaluation of the visual performance of visually impaired and normally sighted individuals under different lighting conditions. To investigate the visual performance empirically, we developed a test involving different adaptation luminance values. A monitor with adjustable brightness facilitated various tests to determine the visual performance as a function of the adaptation luminance and glare. In addition, the subjective impressions of the visually impaired participants were captured via interviews. The study included 98 visually impaired people and 38 people without eye-related ailments. The interview results suggest that most people with visual disabilities require special lighting conditions. An increased lighting requirement is observed amongst 50% of this group. Moreover, 75% of this group display increased glare sensitivity. Likewise, adaptation problems and critical issues related to non-uniform lighting are manifest. Visually impaired individuals display significant in the visual performance variance at different brightness levels. Individuals with eye disease display a greatly reduced contrast threshold and a higher subjective level of discomfort compared to individuals with normal vision. Most visually impaired individuals require a higher degree of brightness to achieve their maximum personal visual performance. About a quarter of these individuals achieves the optimal visual performance at lower brightness, while displaying an increased sensitivity to glare. In general, glare has a decisive influence on the visual performance of visually impaired people. For general lighting purposes, a predominantly indirect lighting source better accommodates these individuals' requirements.

Lighting conditions in physiotherapy centres: A comparative field study

“…Moreover, about one-third of the employees were dissatisfied with artificial light and the overall quality of light, and two out of five of those having a window were dissatisfied with their view. Hauck et al , 48 in their test comparing the visual performance of visually impaired and normal-sighted individuals, found that special lighting conditions were required by most people with visual disabilities, who also showed higher glare sensitivity and adaptation problems related to non-uniform lighting. The latter ones are also highly related to the conditions in physiotherapy centres, where, in particular, elderly people with an increased risk of age-related visual defects, are likely to be present.…”

Inclusão e acessibilidade na arquitetura: revisão sistemática sobre iluminação e baixa visão

“…Avaliando as necessidades de iluminação do indivíduo com perdas visuais, é possível combinar auxílios visuais com estratégias de iluminação para tarefas específicas do dia a dia como: ler e escrever (Munford, 2004); preparar e servir comida (Brunnström et al, 2004); determinar a cor da roupa e mover-se em um ambiente (Barstow et al, 2011); ver-se no espelho, colocar o plugue na tomada e a chave na fechadura da porta (Butler et al, 2019); entre outras. Condições de iluminação desfavoráveis podem dificultar ainda mais a visão residual dos indivíduos com perdas visuais (Hauck et al, 2019). b) Superfície e diferenciação do piso.…”