Myopia among medical students in Norway.

In this study the prevalence of myopia and age at onset among medical students were determined. Of the 140 senior medical students at The Faculty of Medicine, University of Trondheim, Norway, 133 (75 females, 58 males) were examined. Visual acuity was tested and the refractive error was measured using automated refraction and clinical refractive technique. The prevalence of myopia was found to be 50.3% in the right eye (n = 67) without significant difference between female and male students. The refractive state was unrelated to body height. Among the myopic students, the mean equivalent sphere was -2.34 +/- 2.01 D in the right eye (range -9.25 D to -0.25 D). A clear relationship was detected between the current amount of myopia and the age at which corrective lenses were first prescribed. However, as much as 43.3% of the myopic students wearing corrective lenses first received these at the age of about 20 years, indicating a relatively high prevalence rate of adult-onset myopia.