Vision loss is one of the most common problems of later
life. Our built environments should be
designed to enable people of all ages to carry out their activities with
relative ease, safety, and comfort.
Sadly, the needs of older eyes are not always met. The changes in vision due to aging are
different than the changes due to specific eye diseases in younger disabled
people. The loss of focus is a natural
part of aging. Aging eyes need more
light and more contrast to see. Color
perception is also affected.
Aging eyes adjust more slowly to changes in illumination
levels. When moving from a normally
illuminated room into bright sunlight, or entering a dimly lit space from
bright sunlight, the dramatic change results in temporary blindness as the eyes
adjust. The three most common types of
vision loss in older adults are overall blurred vision, central vision loss,
and peripheral vision loss. Those with
overall blurred vision experience increased sensitivity to light, a marked
decrease in the intensity of color, and due to lack of contrast, they may
experience particular difficulty being outside.
For those with central vision loss, images appear distorted and segments
of words may be missing in type, there’s an increased sensitivity to light,
altered color vision, and faces may be hard to recognize. Window coverings and lighting can be adjusted
to reduce bright sunlight. Peripheral
vision loss causes a fear of moving around, so it’s important not to rearrange
furniture. In people with dementia, all the above normal vision problems caused
by aging are even worse. There is a
disproportionate impairment in the discrimination of colors on the cool (blue)
side of the color wheel, and they have difficulty distinguishing between blue
and green and blue and violet. While
these colors may be very calming to the general population, these colors are
not the best choices for dementia settings.
People with dementia also experience depressed contrast sensitivity in
all colors.
Lighting needs for the elderly are quite different from
those of a younger person, and designers have a big challenge to understand
appropriate lighting for long-term care facilities. Vision begins to decline as early as age 40. A 60-year old person may require two to three
times as much light as a 20-year old and the amount of light required doubles
each 13 years after the age of 20. One
of the most important design considerations in the design of senior housing
facilities is lighting. Key design goals
for senior housing projects are as follows:
1.
Provide a higher level of illumination compared
to most spaces designed for the general public.
A combination of low-brightness, direct fixtures, and indirect light
fixtures is one reliable approach for general illumination. Using indirect fixtures that provides a
uniform ceiling brightness and down lighting with the same luminance as the
ceiling is key. A uniformly bright
ceiling is defined as one that has no areas four times brighter than the area
between fixtures; however, because of the extreme sensitivity to glare for
older adults, a 3:1 ratio is preferable.
2.
Provide consistent, even light levels. Pendant indirect lighting and cove lighting
provide the most even illumination and provide a high level of ambient lighting
without glare. Chandeliers and sconces
look nice and provide a homelike feel, which is important, but on their own,
can’t supply the amount of light needed for aging eyes. Recessed down lights also provide poor light
distribution and produce both direct and reflective glare.
3.
Eliminate glare.
There are two types of glare: direct glare and reflected glare. Direct glare comes from inappropriately
shielded light sources such as sunlight streaming in from windows or skylights
in a dimly lit hallway. Daylight should
be balanced and controlled, but should definitely be utilized. When light bulbs are exposed in light
fixtures without proper deflectors or diffusers, it can be especially harsh for
the elderly. Reflected glare comes from
strong light bouncing off a smooth reflective surface such as vinyl flooring,
appearing as “hot spots”. Reflected
glare can be controlled by a skillful selection of paint, wallcovering,
countertops, and other surface materials with matte finishes. Polished surfaces and high gloss paint are
not recommended.
4.
Provide access to natural daylight. Access to interior courtyards, indoor atriums
and greenhouse windows offer greater access to natural daylight. People who rarely see natural light suffer
from illness as well as visual deterioration.
Sunlight stimulates the nervous system, improving appetite and mental
attitude, and induces better sleep. This
is true not only for the general public, but for elderly people and people with
dementia.
5.
Provide gradual changes in light levels. Transition areas should be provided from
spaces with bright daylight to areas of lower light levels or vice versa. Changes in floor level should not occur until
the eyes have had enough time to adjust.
A seating area in an entry vestibule, for example, gives the older
person a place to rest while their eyes adjust.
6.
Provide focused task lighting. Lamps in the 3,500 to 4,000 degree Kelvin
range are best for task lighting. Avoid
direct glare from the light source. If
no local task lighting is available, the general lighting should provide
illumination of about 300 lux (30 footcandles) to 750 lux (75 footcandes) at a
work surface.
7.
Improve color rendition from lights. Cool-white fluorescent lamps are deficient in
both the red and blue-violet areas of the spectrum, and result in color devoid
of warmth and aliveness giving skin a lifeless pallor. Choose lighting that more accurately the true
color of people and objects.
8.
Using natural light. The illumination level for indoor lighting is
typically equivalent to that of twilight.
These light levels are barely adequate to see and not sufficient to send
an effective signal to the biological clock for the regulation of hormones and
circadian rhythms. Daylighting refers to
design solutions that gather, direct, and reflect natural light deep into
buildings. High ceilings, large windows,
and north-facing skylights to maximize natural light while minimizing direct
light are all good strategies. Providing
adjustable window coverings to control natural light is important to reduce
glare.
Statement Design Studio specializes in interior design for
senior housing and memory care facilities.
Contact us at www.statementdesignstudio.com
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