AWA NEWS: “Lighting For The Elderly” Series – Part 3 of 4
Understanding The Aging Eye
The human visual system deteriorates throughout adult life and is considered “young” until it reaches 40 years of age. By understanding how light and lighting can compensate for common changes that happen to the aging eye, designers can improve the quality of life of older adults, especially in assisted living facilities.
Aging of the Visual System:
- Less light reaches the back of the eyes.
- Pupils decrease in size.
- Lens becomes thicker so that it absorbs more light.
Sleep Quality in the Elderly:
- Between 40-70% of people over 65 suffer from chronic sleep disturbances.
- Sleep disturbances result from a disruption of the body’s circadian rhythms.
- Scientists at Rensselaer Polytechnic Institute’s Lighting Research Center [LRC] have demonstrated that blue light is the most effective at stimulating the circadian system.
- This light must be combined with the appropriate light intensity, spatial distribution, timing, and duration.
- A marked increase in daytime lighting levels can counteract the age-dependent losses in retinal light exposure.
Designing Effective Lighting Systems for the Elderly:
- AMBIENT LIGHT LEVELS: These should be increased by 50% versus those used for younger people. Ambient levels should be at least 300 lux.
- TASK LIGHTING: Light levels should be at least 1000 lux on task areas to see fine details.
- CONTRAST: The contrast of objects such as stair edges, curbs, ramps, or doorways should be increased by using paint or other techniques.
- COLOR PERCEPTION: This can be improved by using high illuminance levels and a high color rendering index light source.
Lighting to Improve Quality of Life:
There are many ways to improve the quality of your life as you age. Light, if designed properly, can lead to much higher productivity, higher comfort, and a better sense of safety and security. Here are a few ways that lighting can be used to improve the quality of life:
- Consider getting enough exposure to sunlight in the morning hours. If you live in cold climates with the limited sun in the winters, consider investing in a simple light source that you use for 20 minutes in the morning.
- Consider reducing exposure to electric light at home after sunset, especially light with a cool white or blue tone.
- All lighting fixtures in your personal space should have minimal source brightness. Glare control accessories should also be provided where required.
- The use of dynamic white LED lighting can allow the lighting to respond to the changes in the inhabitant’s environment and should be utilized to reinforce circadian rhythms as well.
- The selection of material finishes can enhance the ability of lighting to create spaces and surfaces that are soothing for the eye, evocative, and provide adequate illumination.
Abhay M Wadhwa
Design Principal l CEO
AWA Lighting Designers