Visual Field Defects May Not Affect Safe Driving

Abstract

Objective: In Quebec a driver whose acquired visual field defect renders them ineligible for a driver's permit renewal may request an exemption from the visual field standard by demonstrating safe driving despite the defect. For safety reasons it was decided to attempt to identify predictors of failure on the road test in order to avoid placing driving evaluators in potentially dangerous situations when evaluating drivers with visual field defects.

Methods: During a 4-month period in 2009 all requests for exemptions from the visual field standard were collected and analyzed. All available medical and visual field data were collated for 103 individuals, of whom 91 successfully completed the evaluation process and obtained a waiver.

Results: The collated data included age, sex, type of visual field defect, visual field characteristics, and concomitant medical problems. No single factor, or combination of factors, could predict failure of the road test. All 5 failures of the road test had cognitive problems but 6 of the successful drivers also had known cognitive problems. Thus, cognitive problems influence the risk of failure but do not predict certain failure.

Conclusion: Most of the applicants for an exemption were able to complete the evaluation process successfully, thereby demonstrating safe driving despite their handicap. Consequently, jurisdictions that have visual field standards for their driving permit should implement procedures to evaluate drivers with visual field defects that render them unable to meet the standard but who wish to continue driving.

Keywords:

• Visual field defects
• Drivers permit
• Road safety
• Visual standards for drivers

ACKNOWLEDGMENT

Thanks are extended to Doctor James McCabe for his editorial comments during the production of this article. This article was the subject of a presentation to The Eye and The Auto in September 2009 in Detroit, Michigan.

Notes

The internal audits referred to in this article are the regular analyses of SAAQ operational statistics that are conducted to evaluate the demand for services and the effects of procedures and policies. The audits serve to identify possible problem areas and examine possible solutions to operational problems. They are not circulated or available to the public.