Hemeralopia in an older adult.

An elderly male was referred for evaluation of hemeralopia when cataract extraction did not alleviate his symptom of difficulty seeing in bright illumination. Visual acuity was 20/40 OU. Funduscopic examination revealed marked arteriolar attenuation, disc pallor, and retinal pigment epithelial changes. Visual fields demonstrated relative paracentral scotomata. An ERG was consistent with widespread photoreceptor degeneration. A diagnosis of visual paraneoplastic syndrome was made and an extensive systemic evaluation revealed a squamous cell carcinoma of the lung. The presentation and evaluation of acquired photoreceptor dysfunction in adulthood is discussed.