Lighting for the Aging Visual System
The light levels recommended for the circadian system should be sufficient for older adults to perform daily visual tasks. In spaces where high circadian stimulation cannot be used, ambient light levels for the aging visual system should be 200-300 lux on the horizontal surfaces (80-100 lux at the cornea) of a neutral light source (i.e., 3000-4100 K lamp). More localized light will be needed to perform tasks that require seeing fine details (e.g., reading prescription bottle labels, chopping vegetables). Architects and specifiers should still provide lighting that gives high, glare-free illumination on the task with no direct or reflected view of the light source, soft shadows throughout the space, balanced illuminance levels, and light sources that provide good color rendering.
Some other lighting principles for the aging visual system that can help architects, specifiers, builders, facility managers, and homeowners37 light interior spaces include:
More light on task areas – Use concentrated light to increase illuminance levels on the task. As much as 10 times more light will be required to see fine details (e.g., reading text with a small font size) or low-contrast objects (e.g., black thread on blue cloth) than is required to see most architectural structures (e.g., doors, cabinets, furniture). Increase light level in areas where visual tasks are performed by placing adjustable light fixtures close to the task, or by selecting lamps with more lumens (look for lumen rating on the package, not wattage; be careful not to exceed the lamp fixture wattage). Increase ambient light levels by keeping surface finishes light in color. Light-colored walls, floors, and ceilings will help minimize shadows and increase overall light levels in the living environment. Place light fixtures where visibility is important, such as below the kitchen countertop, over the kitchen sink, in the shower, and in closet and laundry spaces.
Less glare – Although older adults require more light to see, care should be taken to avoid glare. Glare is experienced when light sources or bright reflections in the field of view impair vision, or are uncomfortable. Very bright lights should not be placed against dark ceilings. The light source itself should be hidden with a shade, baffles, non-shiny louvers, or a shielding board. If a bare lamp is unavoidable (e.g., fan lights), it should be frosted to diffuse the light. In this same vein, clear glass light fixtures should also be avoided. The use of shiny floor finishes and polished surfaces should also be minimized to reduce reflection from light sources.
Balanced light levels – Due to optical and perhaps neural changes in the eye, older adults cannot adapt to dim lighting conditions as well as younger people. As a result, illuminance levels in transitional spaces, such as hallways and entrance foyers, should be similar to those of the adjacent spaces. The ambient light levels in adjacent spaces should be balanced to be approximately the same. Multiple switches or dimmers to create intermediate light levels in transitional spaces that lead from bright, outdoor areas, to dim, indoor spaces should be chosen. Transitional spaces should be dimmer at night and brighter during the day.
Enhanced colors – Color discrimination is poorer for older adults because of scattered light in the eye. The aged lens also absorbs relatively more short wavelength (blue) light, so it is particularly difficult to discriminate between, for example, dark purple and maroon. Use lamps with high lumens and good color rendering properties.
Improved contrast – Because contrast sensitivity is reduced with age, the visibility of important objects, such as stair edges, curbs, ramps, or doorways, can be greatly improved by increasing their contrast with paint or similar techniques. Contrasting colors to mark edges, such as doorframes, baseboards, or steps should be used.
LRC Light & Older Adults website
Figueiro MG. 24-Hour Lighting Scheme for Older Adults. LD+A, 2013.
Figueiro MG. A Proposed 24 h Lighting Scheme for Older Adults. Lighting Research & Technology, 2008.
Figueiro MG. Lighting for Seniors at Hebrew Home, 2013.
Figueiro MG. Lighting the Way: A Key to Independence, 2001.
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