According to the CDC, more than 3.4 million Americans aged 40 years and older are either legally blind or visually impaired. An additional 21 million Americans report functional vision problems or eye conditions that may compromise vision. As we age, we are more likely to experience vision issues due to age-related eye diseases such as cataracts, glaucoma, macular degeneration, diabetic retinopathy, as well as additional vision complications that occur from conditions such as Dementia/Alzheimers disease.
During the next three decades the percentage of adults with vision impairment and loss from these conditions is estimated to double with the rapidly aging population and the rising epidemic of diabetes and other chronic diseases. Vision loss reduces both quality of life and health. It contributes to accidents and falls, especially when compounded by other aging problems such as poor balance and hearing loss. Lighting is undoubtedly the most important factor in designing an interior environment, as seniors become more reliant on the environment to compensate for increasing frailties. Incorporating natural daylight, as well as electric, is critical to promoting both physiological and psychological health – especially in an older population.
Research indicates that incorporating natural sunlight within an interior space reduces depression among residents, and also has a positive impact on staff as well. Natural daylight has a positive effect on circadian rhythm and Vitamin D synthesis. Circadian rhythm is the natural physiological and behavioral pattern and process that takes place in a 24 hour period. This includes your sleep-wake cycle, body temperature, blood pressure, and release of hormones, which is controlled by the hypothalamus, or your biological clock, located in your brain. While we can get the needed light levels for circadian rhythm outside, we usually do not get them indoors – whether it is at home, or within a care community. Conversely, we need darkened spaces in the evening as a signal to our brains that it is time to sleep. In many senior care communities, the light levels (and noise levels) during the evening hours are too high, interfering with biological rhythms.
So what exactly is seen as both a course of normal aging, and with age-related eye disease? As we age the pupils in our eyes become smaller, which reduces the amount of light that enters the eye. As a result, starting around the age of 60, people need almost three times the amount of ambient lighting than those in their 20’s. Conversely, tolerance to glare is reduced as we age. The pupil doesn’t respond as quickly to light and dark, so seniors have a harder time with glare when moving from a dark environment to a bright one. Think of going to a movie during the day, when the theatre is dark, and the time it takes for your eyes to adjust when you emerge into the bright sunlight. The ability of the pupil to respond to this change in light levels decreases with age.
Over time the lens of the eye yellows and hardens, making colors seem yellower than they are in actuality. Clouding of the lens, and subsequent loss of clarity, scatters light and reduces the ability to discern contrast between objects. This has become quite a “Aha” moment for me when I personally had cataract surgery in my left eye. The result is being able to see clearer, brighter, more cool-color spectrum with that eye, and hazier, “yellow” warm spectrum with my right. Interesting tool for an Interior Designer!
With these considerations in mind, what are the interior design implications and best practices that should be implemented to support our rapidly growing aging population?
Next article – Design recommendations to support aging vision.