by Dan Roberts
A couple of changes are on the horizon which may allow visually impaired people to regain or maintain the pleasure of piloting their own private vehicles whenever and wherever they choose.
The most immediate change could come from relaxation of the minimum visual acuity requirements, made possible in part by the development of bioptic telescope devices. The other change is the advent of autonomic (self-driving) vehicles. This article provides comments on both.
In a report to the World Research Congress in 2011, Dr. Joanne Wood said, “Many drivers with moderate vision loss have the potential for safe driving using a bioptic telescope”. And, since driving cessation is associated with loss of independence, depression, and reduced access to employment and healthcare, “denial of a driver’s license to persons with…vision loss, without offering the opportunity to use bioptics, must be questioned”.
And it has been questioned. Five years after Dr. Wood’s report, 48 states are now allowing bioptic driving. 32 of those states actually allow driving with bioptics by people with visual acuities as low as 20/100 to 20/200 (legal blindness). But are they driving safely? A study at the University of Alabama (1) found that 22 out of 23 drivers using bioptics were rated safe to drive. In addition, most people with low vision are evidently imposing their own restrictions on driving, as reported in the Journal of Ophthalmology in 2013. (2)
Another study (3) suggests that there are reasons other than visual acuity for safety issues, such as visual attention and processing speed. Supporting this viewpoint is a review of the literature (4) that assessed the consistency of licensing guidelines with available scientific evidence on the effect of visual impairment on driving. The authors wrote that “driving involves a complex set of skills”, proposing that “decisions about vision for safe driving need to be considered in the context of the driver’s overall health and other functional abilities”.
In other words, using only the standard visual acuity of 20/40 as the basis for granting a driver’s license may be too simplistic, and even unfair, especially when bioptic devices, other functional abilities, and the driver’s tendency to self-regulate are considered. The research has been done. Now changes need to be made through passage of more bills allowing restricted licenses for visually impaired people who are otherwise fit to drive. So far, 17 states are allowing restricted driving by people with acuities as low as 20/200 (5), and others are sure to follow if enough support is shown by voters.
What about drivers whose visual acuity is worse than their states’ limits? Or what if their visual acuities are within the limits, but they are affected by other conditions that would make driving unsafe? Those who are young enough to be able to wait a few more years will almost certainly find hope in the quickly developing field of autonomous vehicles.
Self-driving cars developed by Google in 2010 have traveled more than 300,000 miles without an accident. Statistics show that, if humans were driving those vehicles, they would have had at least two accidents by that time. So autonomous cars are in our near future, probably in the form of taxicabs at first, and eventually as affordable private vehicles when more manufacturers enter the market.
Before we will have the pleasure, however, of having our car pick us up at the front door, take us across town, and park itself until we’re ready to come back home, we have to wait for the world to catch up with the technology. Laws have to be passed, insurance companies have to rewrite policies, and the general public has to get used to seeing drivers safely reading or napping at the wheel.
A motivated person participating in a good low vision rehabilitation program can conceivably preserve or restore 99% of all independent activities of daily living lost to poor vision. (6) With the changes taking place in personal navigation, that percentage will reach 100. Changes in driving regulations will require pressure from the public and the care providers who serve them. Making use of autonomous vehicles will require only enough public interest to amend the current statutes and promise car manufacturers a good profit margin. The day is coming when driving will be a privilege everyone can enjoy, and that day may be closer than we think.
1 UAB bioptic driving study. Joanne Woods, et al (University of Alabama at Birmingham. IOVS, May 2, 2013, ARVO 2013)
2 Driving Habits in Older Patients with Central Vision Loss.
Sabyasachi Sengupta, DNB, FRCS, et al (Ophthalmology. Published online December 2, 2013)
3 Vision Impairment and Driving. Cynthia Owsley, PhD, et al (Survey of Ophthalmology, May 1999, vol 43, issue 6, pp 535-550)
4 Implications of Vision Testing for Older Driver Licensing. Bohensky M, et al (Traffic Inj Prev. 2008 Aug;9(4):304-13)
5. Bioptic Driving: Application and Outcomes to Low Vision Driving. Presentation by Chuck Huss, COMS (West VA Bioptic Driving Program, West VA Division of Rehabilitation Services)
6. An Examination of Sensory Contributions to Independent Activities of Daily Living. Dan Roberts (Published in PDF format at www.mdsupport.org/sensory.pdf )