Prevalence of visual impairment in relation to the number of ophthalmologists in a given area: a nationwide approach.

Background: Sociological and economic risk factors of visual impairment have never been described in France at a national level as the association between the number of ophthalmologists per inhabitant and visual impairment prevalence.

Methods: Two national surveys were pooled. First, 2075 institutions were selected at random from the French Health Ministry files.