Assistive technologies offer patients with low vision a chance at independence—and nowhere is that more impactful than on the road. The inability to drive due to vision loss can be the deciding factor in someone’s ability to care for themselves, and factors greatly into quality of life. For the past 40 years, the primary driving solution for low vision patients has been bioptic telescopes. However, today’s global positioning system technologies are offering new options, argues a literature review recently published in Optometry and Vision Science.

According to the authors—an OD and a mechanical engineering PhD, both from the University of Iowa—the traditionally used bioptic telescopes aren’t all they’re cracked up to be. To use one, a patient is fit with a pair of glasses with one lens that has an extra-powerful portion. This helps the patient read distant signs and monitor traffic, but binocular vision is compromised. Patients must train to use this device while maintaining peripheral awareness with the rest of the visual field. The researchers say this is a recipe for distracted driving.

“We now know from human factors and attention research that the assertion that an individual can attend to two tasks simultaneously is not possible,” the publication reads. “With bioptic telescopes, there is a ‘switching’ of visual attention and change in head pose when using such devices—both of these remove vital attention from the forward roadway,” it continues. “In addition, inattention blindness, when cognitively distracted, can reduce the driver's ability to see and process important hazards in the road. Bioptic telescopes exacerbate this effect even further because they can virtually eliminate the user's peripheral awareness when viewing through the telescope.”

Having noted the problem, the investigators turned their attention to newer technologies that can even be found standard on some vehicles: advanced driver assistance systems. These include lane departure warnings, lane keeping (where the car will resist a lane drift), adaptive cruise control (that adapts the driver's speed and brakes to match the speed of the vehicle ahead), automatic emergency braking, left turn across path crash avoidance (where the car will brake to avoid a left turn across path crash) and blind spot detection.

With all these features on the market and already demonstrating safety improvements for the general public, the research team is asking whether low vision drivers even need the bioptic telescopes any longer. “With these technologies, all drivers, including older individuals and individuals with vision loss, can be expected to drive more safely,” the team proposes.

“The switching of view within the bioptic spectacles is attentionally demanding, and the visual field restriction of such devices reduces overall situation awareness by narrowing the driver's attention,” they conclude. “Advanced driver assistance system technologies can […] help prevent or reduce the severity of a crash.”

The next step, they say, is comparing bioptic telescopes with modern technologies.

Wilkinson M, McGehee D. Auditory global positioning system and advanced driver assistance systems: a safer alternative to bioptic telescopes for drivers who are visually impaired? Optom Vis Sci. December 29, 2018. [Epub ahead of print].