To what extent do cataracts and cataract surgery change perception?

Cataract surgery is the most commonly performed surgical procedure worldwide and is typically associated with an improvement in visual acuity (VA). This study aimed to examine how various visual functions, beyond VA and contrast sensitivity, are affected by cataracts and how they change after cataract surgery. We assessed 28 adults (aged 55-85 years) with vision-impairing cataracts using a comprehensive battery of visual tests at four visits: before surgery, 1 week after surgery of the first eye, 1 week after surgery of the second eye, and 1 month after the second surgery. Tests included VA, contrast sensitivity, coherent motion (CMot), orientation discrimination, visual search, and reaction time, assessed monocularly and binocularly. Both a cognitive and a self-assessment questionnaire were administered at the first and last visits. Results indicated that cataracts impaired all visual functions except CMot. Postoperatively, VA, contrast sensitivity, and CMot improved significantly, with marginal gains in orientation discrimination and no change in visual search or reaction times. Improvements were greater after the first surgery. Also, stronger correlations between low-level visual functions, cataract severity, and self-assessment scores were observed for the first operated eye. Cognitive scores correlated significantly with performances in CMot, orientation discrimination, and visual search. These findings suggest that cataracts strongly affect low-level visual processing, whereas higher-level tasks may be maintained through cognitive compensation. Cataract surgery recovers performance in most but not all visual tests, highlighting the importance of considering visual function beyond VA, as well as cognitive functioning, in ophthalmic clinical care.