Untreated vision loss was added to the Lancet Commission framework in 2024 with an estimated population-attributable fraction of approximately 2%. The biology parallels hearing loss closely — sensory deprivation increases cognitive load, withdrawal from cognitively enriching activities accelerates the trajectory, and the visual cortex may undergo accelerated changes when input is degraded. The intervention is straightforward and the evidence is encouraging: corrective interventions for vision loss appear to reduce dementia incidence in observational work, with cataract surgery showing the most consistent signal.
Cataract surgery has emerged as a notable cognitive intervention. Observational studies have consistently shown that older adults who undergo cataract surgery have lower incidence of subsequent dementia compared to those who do not. The size of the effect varies by study, but the consistency of direction is striking. The biological rationale is plausible — restoring clear vision allows continued engagement in reading, social interaction, environmental navigation, and the cognitive activities that build and maintain cognitive reserve. The clinical implication is that cataract surgery should be considered actively rather than passively when indicated, particularly in patients in the acceleration window or with any cognitive concerns.
The vision workup in longevity psychiatry includes more than cataract assessment. Refractive error should be corrected to current best acuity. Macular degeneration screening (Amsler grid, optical coherence tomography when indicated) identifies a treatable but progressive condition. Glaucoma screening identifies a treatable cause of visual field loss that often progresses silently. Diabetic retinopathy in patients with metabolic disease. Each of these conditions, when treatable, deserves treatment specifically with cognitive trajectory in mind, not just visual function.
The clinical practice is to ask about vision actively rather than wait for patients to report problems. Patients often adapt to gradual vision changes without recognizing them — "I just need to hold the book farther" or "I don't drive at night anymore" — that mark progressive impairment normalized into daily life. The longevity-psychiatry workup includes recent comprehensive eye examination as part of baseline assessment, with annual follow-up beyond age 60. Referral threshold should be low for any patient with cognitive complaints, recent functional changes, or family history of vision-affecting conditions.
The integration with hearing loss matters clinically. Many older adults have both vision and hearing impairment — combined sensory loss that compounds the cognitive risk through accelerated social withdrawal and increased cognitive load on degraded input across both modalities. Treating both is more effective than treating either alone, and patients with combined impairment often benefit even more from intervention than patients with either impairment alone. The clinical workup that asks about both senses, screens both modalities, and intervenes on both as indicated captures more of the available benefit than the typical workup that addresses each in isolation.