Employ reverse contrast by using brighter print on a darker background, thus offering the same contrast but drastically reducing the total flux entering the eye. Light only the areas where light is needed. Adaptation control is important. The time required to adapt to changing light levels is much longer for the aged. This means going from bright areas to dark ones, and the reverse, can be a real problem.
Good visibility is difficult when moving between spaces lighted at very different light levels.
The adaptation time is longer when going from bright to dark than the reverse. One example seen frequently these days is in going from an overlit service station back out onto the street or highway. Similar differences can be seen when going from overlit entryways to walkways or parking lots. Large differences in light level should be minimized in transition areas, such as building entrances, parking lots, walkways, and streets. While differences in light level are important in any lighting design, they are of paramount importance for the elderly.