EFFECT OF VISUAL IMPAIRMENT ON NEUROPSYCHOLOGICAL TEST-PERFORMANCE

Three vision-dependent neuropsychological tests of visual processing - Benton's Facial Recognition (FR), Judgment of Line Orientation (JLO), and Visual Form Discrimination (VFD) - were administered to subjects on the same day as routine ophthalmic examination. Seventeen subjects had Jaeger near vision of J5 (analogous to 20/50) or worse resulting f rom refractive error, while 13 control subjects had normal near vision of J1. Neuropsychological test scores of thesegroups were compared wi th each other and also the published standardization group for each te st. Low near-vision subjects' performances on FR and VFD were signific antly poorer than both control group subjects and standardization grou p subjects, but performance on JLO was not significantly altered. Thes e results demonstrate that visual impairment can result in unexpectedl y low scores on certain tests of visual processing, which suggests tha t poor vision might alsoaffect results of other neuropsychological tes ts that involve vision, such astests of visual processing and tests wh ich use vision as a vehicle to delivertest stimuli to the relevant por tions of the cortex. We therefore strongly urge examiners to secure co ntrol over potential bias resulting from reduced vision by instituting routine near visual acuity testing of all subjects prior to or during neuropsychological assessment.