Lateral control modeling of bioptic telescope drivers

The ability to utilize a motor vehicle is paramount in modern society. The impact of driving and the relationship it has with personal independence and quality of life is crucial. In the United States, people with a corrected visual acuity worse than 20/40 are denied general licensing to operate a car. Although, in over 40 states those who do not meet general visual acuity requirements and have low vision are able to gain special licensure through the use of a bioptic telescope. A bioptic telescope is a miniature telescope mounted to a carrier lens that allows the user increased vision capacity. The rationale behind the use of a bioptic telescope for driving is that it provides the driver with low vision the ability to view objects and assess their surroundings while driving in a safe manner that they otherwise would not be able capable of.

Little research has been conducted to assess bioptic drivers in relation to the normal driving population and to people with similar visual acuity licensed without a bioptic. Prior research has returned mixed results on the safety and application of bioptics for driving. The nature of visually impaired driving is a constant additional workload to baseline driving. The workload and attention demand imposed by low vision and bioptic driving is analyzed through lateral control modeling of steering wheel reversals to assess baseline driver performance in an on-road driving experiment.

From the results, the study found that driving with a bioptic system and low vision significantly differs from the normal population in regard to lateral control. The attention demand and workload required by driving with a bioptic system was found to be elevated compared to the normal population and non-bioptic visually impaired drivers. With bioptic system users committing steering corrections at a higher frequency than the normal population. The study also found that even though the corrections made by drivers who use a bioptic are significantly larger than the normal sighted population, the steering corrections were not significantly different than visually impaired non-bioptic system drivers. In fact, non-bioptic visually impaired drivers were found to commit significantly larger reversals than visually impaired drivers who use a bioptic.

Furthermore, it is apparent that visually impaired drivers exhibit more workload and attention demand while driving. The comparison between bioptic and non-bioptic visually impaired drivers did not deem the presence of a bioptic system to decrease driver safety in baseline driving. Future work should be done to assess the workload and performance of drivers who use a bioptic during explicit cases of bioptic use, such as sign scanning or object detection by incorporating a suite of lateral control metrics.