Background: While the number of individuals with visual impairment in Japan has shown a declining trend nationally, substantial regional variations in temporal patterns may exist. Objective: To analyze regional variation patterns in the number of individuals with visual impairment across prefectures using panel data collected at five-year intervals from fiscal year 2003 (Heisei 15) to fiscal year 2021 (Reiwa 3), and to identify region-specific trends. Methods: Data on the number of individuals with visual impairment (total, under 18 years, 18 years and older) from all 47 prefectures were obtained from the government statistics portal (e-Stat). Rates of change were calculated for each period, and regions with deviations exceeding two standard deviations from the mean were identified as statistical outliers. Results: Nationally, the number of individuals with visual impairment decreased by 17.01% over the 18-year period (from 388,326 to 322,260). However, Kanagawa Prefecture (+12.51%) and Tokyo (+7.89%) showed increasing trends. Conversely, marked decreases exceeding 50% were observed in Yamaguchi Prefecture (-57.21%), Aomori Prefecture (-56.05%), and Nagasaki Prefecture (-55.60%). Okinawa Prefecture exhibited a sharp decrease of -31.65% during the period from fiscal year 2012 to 2016, while Akita Prefecture showed a notable decrease of -35.74% from fiscal year 2016 to 2021. Among individuals under 18 years of age, dramatic decreases were observed in Tottori Prefecture (-80.56%), Hyogo Prefecture (-77.05%), and Yamagata Prefecture (-75.51%). Conclusions: Temporal variations in the number of individuals with visual impairment in Japan differ substantially by region, with a polarization trend characterized by increases in major metropolitan areas and rapid decreases in rural regions. The abrupt changes observed during specific periods in Akita, Nagano, and Okinawa prefectures suggest potential influences of changes in healthcare systems, differences in the application of diagnostic criteria, or demographic factors.

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