Preferences of People with Vision Impairment with Respect to Visibility of Elements in the Built Environment

The qualities of the built environment impact on the ability of people with vision impairment to move safely through the environment. It is important to revisit the evidence of the relationship between vision and the visibility of elements in the built environment to ensure accessibility standards and design guidelines are consistent with the latest evidence base. This paper reviews mixed method (qualitative and quantitative) research into visual and non-visual factors known to be implicated in injurious incidents in people with vision impairment. The evidence base for the visibility of simulated and real environmental elements such as stairs, doors, door handles, light switches, tactile ground surface indicators, traffic cones, road line markings and pedestrians will be reviewed. The evidence suggests that luminance contrasts of approximately 2.5× current contrast standards, as current standards vary, would allow people with up to severe vision impairment to see objects of the dimensions of tactile ground surface indicators with ease. If people who are categorised as being blind by WHO are considered, about 3× current contrast standards may be required. If lower contrasts are used, alternative provisions should be made to assist people with vision impairment to navigate the space safely.