Whether you’re 25 or 75, you may have experienced the effects of aging on your eyesight — and it tends to get worse as the years go by. Typical age-related eye pathologies — including macular degeneration, cataracts, glaucoma and retinopathy — contribute to reduced contrast sensitivity, slow light-dark adaptation, visual field loss and diminished visual acuity and depth perception.
Certain mood and sleep disorders typically seen in older people are associated with changes in vision and the way aging eyes and brains process light. These include various forms of depression, sleep disorders and dementia. Much work has been done in developing specific light therapies to address many of them. According to the authors of “A Systematic Review on the Therapeutic Lighting Design for the Elderly,” the following have proven most effective.
The authors of the “Systematic Review” — all professors of building engineering at Loughborough University in the U.K. — assert, “These theories [cited in the table above] can enhance the existing lighting design practice by incorporating therapeutic lighting performance into integrated lighting systems. However information regarding therapeutic lighting is scattered and not discussed in detailed guides.”
They’re not the only ones to notice. In a paper titled “Lighting in Nursing Homes,” Eunice Noell-Wagoner of the Center of Design for an Aging Society in Portland, OR, takes issue with the lack of building code standards for elder-care facilities: “I have yet to find any national regulations requiring the quantity and quality of light to meet the needs of older people in their communities or in nursing homes specifically. The photobiological effects are not addressed at all.”
So, how can we make things better in existing facilities? Facility managers and caregivers can take some cues from the effective therapies outlined above and start reading the labels on the lightbulbs installed in residents’ living quarters and common areas. In short, you can make the most of available resources.
Some technical background on lighting dimensions
Let’s start with what we can infer from the table listing therapeutic lighting treatments above.
In the table column with the heading “Light Output,” there are specific recommendations for the amount and color of light prescribed to address each condition. In technical terms, light output is measured in a number of dimensions, each expressed by a distinct unit or classification:
Lumen is a unit of light flow, often used to characterize the amount of light emanating from a bulb or fixture
Lux is the metric unit for the illuminance of a surface; 1 lux is equal to 1 lumen per square meter. Color temperature can be expressed in quantitative terms in K (Kelvin) or with a number of different verbal classifications, including those on a scale from warm (2700 K) to cool (6500 K).
Another commonly used system classifies color temperature outputs as Warm White (reddish to yellowish), Bright White (yellowish to whiter) and Daylight (white to blue).
With a basic understanding of these expressions, you can begin to interpret the “Therapies” table. Generally speaking:
- Bright, high-intensity lights tend to offer more therapeutic benefits for the elderly than standard levels of illumination
- Bright blue combined with dim red lights alleviate depression
- Bright blue combined with moderate yellow lights can alleviate sleep disorders
- Gradually increasing illumination from dark to moderate light at or before dawn can help to normalize sleep to waking cycles
Selecting lightbults by labels
While there are many different types of lightbulbs to choose from, including compact fluorescents, incandescents, halogens and HIDs — and many reasons to select one type instead of another — they all come packaged with labels like the one above, which provides information about their output. This makes it possible for lighting laypersons to match the brightness and color temperature of bulbs to desired therapeutic effects. Look for comparatively high lumens of output for applications requiring bright lights and use the indication on the Light Color scale to match color temperature to the therapeutic goal.
It’s true that effective lighting design for senior facilities is not really that simple. We’ve got to leave it to the pros to create integrated designs for daylighting, ambient, task and emergency lighting with controls for adjusting to appropriate levels throughout the day. But awareness of the possibilities and improving light bulb selection where possible is a good way to serve those you care for.
And a final thought from Eunice Noell-Wagoner of the Center of Design for an Aging Society: “When administrators hear that lighting is important from a marketing aspect, they will implement the change to appropriate lighting more quickly.”
Michael Chotiner, an ex- general contractor and home improvement author, likes to write about DIY projects for The Home Depot. Michael also likes to provide tips on how to pick the best light bulbs for your home.