In 2009, 39.6 million Americans were 65 or older; by 2030 this number is expected to grow to 72 million. By 2025, 40% of our population will be over age 55. Starting at around age 40 our vision begins to decline: the lenses of our eyes thicken and become more yellow to brown, which creates distortion in color perception. The pupils of our eyes also become smaller and less responsive to light. It is important that we understand the lighting challenges that our aging population presents and provide viable solutions that will improve the general health, emotional well-being, and quality of life of our parents and grandparents.
Older eyes need more light, especially for distinguishing fine details. The Illuminating Engineering Society of North America (IESNA) recommends that people who are 65 and older need four times the amount of light that individuals who are 25 years old and younger.
Increase the general light level in the space. This not only helps seniors see better, it also helps them stay awake during the day and thus, improves their daily sleep cycles. In fact, well-regulated day/night lighting cycles have been shown to reduce night wandering in Alzheimer's patients by as much as 50%.
Improve the uniformity of the light distribution in the space to reduce shadows.
Avoid the "drama" of bright and dark areas in the space. Bright and dark spaces often create a highly effective lighting design for "normal" eyes but usually not for aging eyes. In fact, this type of dramatic lighting can sometimes be disorienting to older individuals.
Use light colored surfaces (ceiling, walls, floor, furniture, etc.) in a space in order to maximize the amount of light in that space.
Use daylight whenever possible and introduce it into the space from more than one direction (skylights, opposing walls) and balance it with the available electric lighting. This will greatly help to immerse the space with light and, thereby, minimize shadows. Also very important, the additional daylight will provide significant health and emotional benefits to older adults.
Indoor stairwells and outdoor stairways should be illuminated especially well to improve safety and avoid risky falls. In addition to maintaining good general lighting in these areas, it would be a good lighting practice to add a number of strategically-placed step lights.
At night the use of several in-wall and/or plug-in night lights in bedrooms, bathrooms, and kitchens would be very helpful for navigating these spaces. Furthermore, to avoid interrupting the circadian rhythms of older adults it is preferable that the night lights provide an amber-reddish light rather than a bluish-white light.
Whenever possible it is advisable to install easy-to-use lighting controls. This not only allows a senior to carefully adjust the amount of light that he/she needs for a given situation it also gives a senior a valuable sense of independence.
Despite the fact that seniors need more light to see, glare can be a real problem for older eyes. Over time, the lenses of our eyes develop opacities that are prone to scatter light, resulting in greater sensitivity to glare to the point of possibly becoming very disabling. Also, mature eyes take longer to adapt to significant changes in light levels.
Light levels should be high but uniform within each space.
Light levels should be reasonably consistent when going from space to space.
Provide a transition zone of "medium-brightness" lighting when traveling from a brightly-lit space to more dimly-lit space and vice-versa.
If skylights are utilized in the space, they should use diffused glass or plastic rather than clear transparent materials to avoid sunlight glare.
Reduce direct and indirect (reflected) glare wherever possible, including from walls and floors. In general, highly-polished hard flooring should be avoided.
Position TVs, computer monitors, and work surfaces to avoid reflected glare.
Task lighting should be well shielded from older eyes by using a variety of opaque shades and/or louvers.
If possible, task lighting for reading, sewing, working on crossword puzzles, etc. should be located above and behind the person and should provide multiple levels of brightness.
Use indirect lighting whenever possible (e.g., cove lighting, valence lighting, suspended indirect light fixtures, wall washers, and torchieres).
If wall sconces are used, they should be well-shielded from direct view of the light source.
Use multiple "layers of light" in a space by using task lighting, accent lighting, general lighting and decorative lighting with a little "bling" as long as the latter does not provide too much direct glare.
Avoid using bare or exposed light bulbs.
Avoid using light fixtures with bright lenses or shiny louvers.
Older eyes have difficulty distinguishing contrasts.
Use color contrasts or light/dark contrasts wherever possible. It is especially important that handrails be a contrasting color from the wall to which they are attached, that floor molding be a contrasting color to the colors of the floor and walls, and that the edge of steps be a contrasting color to the steps themselves.
Use light sources with high color rendering capabilities with a Color Rendering Index (CRI) of 80 or above. Thus, when looking to replace fluorescent light bulbs, for example, be sure that part of the lamp code or lamp description includes "830" or "80+".