To better understand the history and epidemiology of Bartonella henselae infections of the eye and adnexa, and their relationship to cat scratch disease (CSD). We also assess B. henselae infection as a public health threat.We reviewed the available literature concerning B. henselae infections of the eye and CSD, and attempted calculation of the incidence and prevalence of both B. henselae eye infections and CSD from the database of the Rochester Epidemiology Project.It took nearly a century of determined effort to reveal that Henri Parinaud's oculoglandular syndrome (POGS) (1889) and Leber's stellate retinitis (1916) were the result of B. henselae infection and are subtypes of CSD. These ocular infections remain of clinical, epidemiologic, and public health concern to ophthalmologists with many unanswered questions. Their incidence and prevalence have yet to be accurately determined. Our attempt to achieve this through the Rochester Epidemiology Project database suggests a major obstacle is inconsistent with nonunanimous diagnostic terminology and coding.Modern serologic testing and molecular diagnostic techniques offer ophthalmologists the opportunity to make B. henselae infection of the eyes an area of "precision medicine." For this to happen, greater awareness and teaching about this disease, updated terminology, and a greater clinical and research effort are required.