From the Desk of Spencer Thornton, MD
Driving & Ocular Health
June 13, 2011
In less than twenty years more than twenty percent of licensed drivers will be 65 or older, according to the Government Accounting Office. The GAO claims their number will nearly double, from 30 million today to about 57 million in 2030.
Technical changes such as smarter cars and better designed roads may help keep seniors driving longer, but eventually most people will outlive their driving ability — men by an average of six years and women by an average of 10 years. And since fewer Americans relocate when they retire, many of them probably will continue to live in suburban homes.
As people get older and feel less able to drive, they narrow their circle of friends and their circle of activities until it gets to the point where they are house-bound and they don't move at all.
The result has been called a "mobility gap," with older people forced to depend on others for transportation and therefore limited more and more to their homes when these “care giving drivers” are unavailable.
If they’re healthy, older drivers aren't necessarily any less safe than younger drivers. But many older drivers are likely to develop age-related medical conditions that can affect their driving including tear film disruption (dry eyes), cataracts, macular degeneration, glaucoma and diabetic retinopathies.
Eye health has become a major concern especially for aging boomers, and nutritional supplements designed specifically for the eyes have gained more attention.
Scientific studies have shown that a 60-year-old needs more light to see at night to see than a 40-year-old. Older drivers generally are less able to judge speed and distances, their reflexes are slower, may be more easily distracted and they're less flexible, affecting their ability to turn to look to the side or behind them.
Fatal crash rates for older drivers compared with other age groups begin to increase starting at about age 75, according to the Insurance Institute for Highway Safety, and drivers over age 85 even have a worse fatality rate than teenagers. The main reason, according to the institute, appears to be that older drivers are less resilient and less likely to recover from injuries.
Nevertheless, the fatal crash rate for older drivers has declined over the past decade, and at a faster rate than for other drivers. Researchers of the insurance institute believe the reason for the trend isn't clear, but it may be that older drivers are in better physical condition, both because of better nutrition and greater emphasis on an active lifestyle.
Many older drivers compensate for the decline of their driving abilities by changing their driving habits, deliberately slowing down and planning their route of travel before leaving the home. Many don’t go out if it’s raining, and some limit their driving to daylight hours. But for some seniors, even though public transportation or “free rides” are available, the car is a symbol of freedom and independence.
Auto-makers are aware of the need for larger dials and better dashboard lighting. And a larger rear-view mirror can help drivers avoid turning around as much. Better designed roads may help. For example, "roundabouts" that gently ease drivers into turn circles with no traffic lights could help reduce left turn-related crashes, which make up a disproportionate share of the accidents of older drivers.
Seventy-five percent of older drivers live in suburban or rural areas where there are few alternatives to driving, and public transportation isn't a realistic option, as the physical and mental conditions that made driving untenable also likely preclude walking to the bus stop, especially if there's no bench. The act of getting on and off a bus can be prohibitive. Many older people, especially those over 80, also worry about losing their balance on a bus and fear being victimized.
Night vision is one of the most frustrating problem for older drivers . The January 21, 2011 Biosyntrx Friday Pearl pointed out that a study published in Vision Research by Drs. Bernstein, Delori and Richer suggested that zeaxanthin's ability to absorb blue light was found to make night driving easier for the older adults who participated in the study.
There are no clear answers, but driving is important to the independent senior, and staying active, good nutrition and lifestyle adjustments may just make the difference.
Spencer Thornton, M.D.
Bernstein, P, Delori F, Richer S, et al. The value of measurement of macular carotenoid pigment optical densities and distributions in age-related macular degeneration and other retinal disorders. Vision Research, Oct 23, 2009 [abstract]
Tong L, Waduthantri S, et al. Impact of symptomatic dry eye on vision-related daily activities: the Singapore Malay Eye Study. Eye. 2010 Sep;24(9): 1486-91- [abstract]