Abstract
Purpose: :
Currently, there are 34 states in the US that have legalized the use of bioptics to aid low vision patients while driving. A bioptic is a telescope mounted on the upper portion of an eyeglass lens. When the driver is using the bioptic for normal viewing, the user looks through the non–telescopic portion of the lens. When extra magnification is needed, the user tips their head downward and brings the item of regard into the telescopic view. In certain states, bioptics allow patients to obtain drivers licenses when they would otherwise not meet the minimal visual standards to drive. The necessary skills required of a safe driver involve more than just vision. Driving is a complex task involving motor and cognitive skills. As we age, cognition and motor function may decline. There is data to indicate that there is an increase in crash rates for older drivers and that this increase rate is directly related to physical and mental changes.
Methods: :
We tested 25 patients between the ages of 51 and 89 years that met criteria in the state of Illinois to qualify for driving with bioptics based solely on visual acuity. These subjects were given 3 tests involving cognitive and motor fitness (Motor–Free Visual Perception Test [MVPT], Trail Making B and Motor Reaction Time Test).
Results: :
Of the 25 patients, 16 were tested with the Trails B Test. Of those patients, 4 obtained scores in the bottom 25th percentile, 6 scored in the 25–49th percentile, 4 scored in the 50–74th percentile, and 2 scored above the 75th percentile. All 25 patients were tested with the Motor Reaction Time Test. 5 subjects obtained scores below the 25th percentile, 16 scored in the 25–74th percentile, 2 subjects scored in the 75–89th percentile and 2 scored above the 90th percentile.
24 of the 25 subjects were tested with the MVPT test. Of these, 14 subjects received raw scores that were passing and 10 subjects failed.
Conclusions: :
Although all 25 patients met the visual requirements to drive with a bioptic, our data would indicate that vision testing alone is not adequate for certifying older low vision patients to drive with a bioptic.
Keywords: low vision • neuro-ophthalmology: cortical function/rehabilitation • aging: visual performance