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Vision is the primary sensory input on which the driver depends. A decrease in visual skills with age could be an important causal or contributory factor in the driving difficulties experienced by the older driver. The crystalline lens within the eye shows functionally significant changes with age. It loses its elasticity, causing a decrease in the ability of the eye to accommodate or change focus. This loss begins around the age of 40, typically being compensated for with glasses or bifocals, and is complete by the age of 60 to 65. The lens yellows with age, contributing to changes in color vision, decreased light sensitivity, and decreased visual acuity. Glare susceptibility is increased. Cataracts, usually age related, should be removed and the optical power of the lens replaced by glasses, contact lenses, or implants. The pupil of the eye becomes smaller with age and loses its ability to dilate in dim light. Many disorders of the retina are associated with age. In the absence of disease, corrected visual acuity remains relatively constant from ages 20 to 50. After 50, corrected acuity begins to decrease, with a rapid decline after 60. The critical flicker frequency (CFF), the flicker rate beyond which flickering of light cannot be detected; dynamic visual acuity; and color discrimination show age-related declines. There is evidence of diminished cognitive capabilities, visual spatial judgment, and visually based motor responses with age. The purpose of this paper is to examine whether current vision standards and screening procedures for drivers are appropriate for identifying those with significant visual disabilities that are unsafe for driving. The following areas are covered: current state of the art in vision screening for driver licensure; relationship of vision and driving performance; bases for visual standards and screening procedures; vision screening implementation issues; merits of various aspects of vision screening; vision-screening policy decisions; recommended driver vision screening and standards; and research needs with regard to visual acuity and visual field tests.

This paper appears in Transportation Research Board Special Report No. 218, Transportation in an Aging Society: Improving Mobility and Safety for Older Persons, Volume 2 - Technical Papers.

pp 294-324

1988

Transportation Research Board Special Report

0-309-04664-5

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Figures (2) ; References (53) ; Tables (1)

Aged drivers; Color blindness; Driver licensing; Drivers; Eyeglasses; Future; Glare; Headlamps; Implementation; Lenses (Optics); Night vision; Persons with disabilities; Policy; Recommendations; Research; Standards; State of the art studies; Vision; Vision disorders; Vision tests; Visually impaired persons

Bioptic telescopic lenses; Future research

Highways; Planning and Forecasting; Policy; Research; Safety and Human Factors; I72: Traffic and Transport Planning; I83: Accidents and the Human Factor

TRIS, TRB, ATRI

Nov 30 1989 12:00AM

• CRASH PROTECTION FOR OLDER PERSONS
• DRIVER AND PEDESTRIAN TRAINING
• HEADLAMP PERFORMANCE FACTORS AFFECTING THE VISIBILITY OF OLDER DRIVERS IN NIGHT DRIVING
• IMPROVING SAFETY FOR OLDER MOTORISTS BY MEANS OF INFORMATION AND MARKET FORCES
• POTENTIAL IMPROVEMENTS IN ROADWAY DELINEATION FOR OLDER DRIVERS
• RENEWAL LICENSING OF OLDER DRIVERS
• SIGN LEGIBILITY AND CONSPICUITY
• SIGNIFICANCE OF MOBILITY FOR THE WELL-BEING OF THE ELDERLY
• THE MOBILITY NEEDS OF THE ELDERLY
• THE SAFETY OF OLDER PERSONS AT INTERSECTIONS
• VISION ASSESSMENT TECHNOLOGY AND SCREENING OLDER DRIVERS: PAST PRACTICES AND EMERGING TECHNIQUES