DIN EN ISO 24502:2011-04

Although the proportion of older people is increasing in many countries, the care for better visibility of signs and displays is not sufficiently taken for those older people. This prevents older people from actively being involved in social activities, as well makes it more difficult for them to be able to live their lives safely and comfortably. This International Standard provides a method of calculating age-related luminance contrast that can be used for assessing and designing signs and displays in our visual environment, so that they are clearly visible to older people. This method calculates age-related luminance contrast for people aged from 10 to 79 years based on age-related photopic spectral luminous efficiency of the eye. This International Standard supplements the principles of accessible design given in ISO/IEC Guide 71. This International Standard specifies the age-related luminance contrast of any two lights of different colour seen by a person at any age, by taking into account the age-related change of spectral luminous efficiency of the eye. This International Standard provides a basic method of calculation that can be applied to the design of lighting, visual signs and displays. It applies to light, self-luminous or reflected, in visual signs and displays seen under moderately bright conditions called photopic vision/day vision and whose spectral radiance is known or measurable. It does not apply to light seen under darker conditions called mesopic (twilight) or scotopic (night) vision. This International Standard specifies the luminance contrast for people aged from 10 to 79 years who have had no medical treatment or surgery on their eyes that may affect their spectral luminous efficiency. This International Standard does not apply to visual signs and displays seen by people with colour defects whose spectral luminous efficiency is different from those with normal colour vision, nor those seen by people with low vision.