Literacy is an independent risk factor for vision impairment and poor visual functioning.

PURPOSE: People with limited literacy are at increased risks of chronic systemic conditions. The authors therefore investigated the independent contribution of limited literacy on visual impairment and visual function in a large eye survey in Singapore.
METHODS: The authors undertook a population-based, cross-sectional study of Asian Malays (≥ 40 years old). Visual impairment was defined as logMAR (logarithm of minimal angle of resolution) visual acuity > 0.30 in the better-seeing eye. Information regarding reading and writing literacy levels and other independent variables, including sociodemographic measures (e.g., education, income), were obtained from a standardized interview. Visual functioning was assessed using a modified and validated version of the Vision-Specific Functioning Scale using Rasch analysis.
RESULTS: Of the 3280 participants, 553 (16.9%) had inadequate reading literacy and 688 (21.0%) had inadequate writing literacy. In multivariate analysis, persons with inadequate reading literacy were more likely to have presenting visual impairment (odds ratio [OR] = 2.66; 95% confidence interval [CI] = 1.91 to 3.72; P < 0.001), best-corrected visual impairment (OR = 2.59; 95% CI = 1.70 to 3.96; P < 0.001), and poorer visual functioning (β coefficient = 0.58; 95% CI = 1.57 to 3.02; P < 0.001), even controlling for education, income, and other patients' characteristics. Similar associations were found for inadequate writing literacy.
CONCLUSIONS: Inadequate literacy is independently associated with visual impairment and poorer visual functioning. Interventions that address literacy may help to reduce socioeconomic disparities in visual impairment.