To investigate the impact of different levels of simulated visual impairment
on the cognitive test performance of older adults and to compare this with previous findings in younger adults.
Cognitive performance was assessed in 30 visually normal, community-dwelling older adults (mean = 70.2 ± 3.9 years). Four standard cognitive tests were used including the Digit Symbol Substitution Test, Trail Making Tests A and B, and the Stroop Color Word Test under three visual conditions: normal baseline vision and two levels of cataract
simulating filters (Vistech), which were administered in a random order. Distance high-contrast visual acuity and Pelli-Robson letter contrast sensitivity
were also assessed for all three visual conditions.
significantly impaired performance across all cognitive test performance measures. In addition, the impact of simulated cataract
was significantly greater in this older cohort than in a younger cohort previously investigated. Individual differences in contrast sensitivity
better predicted cognitive test performance than did visual acuity.
Conclusions. Visual impairment
can lead to slowing of cognitive performance in older adults; these effects are greater than those observed in younger participants. This has important implications for neuropsychological testing of older populations who have a high prevalence of cataract