Refractive errors in a Finnish rural population.

Refractive errors in 611 persons living in a rural area were examined. Males numbered 281 and females 330. The age range was from 6 to 85 years. In 73 (11.9%) persons the refraction was myopic (SER less than or equal to 0.5 D) and in 173 (28.3%) hyperopic (SER greater than or equal to + 2 D). Myopia was most frequently detected in persons aged 21-30 years (22.6%), and the proportion of myopia decreased towards both extremes of age. In all age groups females were more myopic than males. In persons aged 21-60 years the most educated proved to have more myopia and less hyperopia than those with less education. In 158 (25.9%) of the eyes, astigmatism was detectable. The degree of astigmatism changed little with advancing age and was independent of sex. In myopic eyes the range of astigmatic error was wider than in hyperopic eyes. The axis of + cylinders was in hyperopic eyes mostly horizontal and in myopic eyes vertical. Anisometropia of 1.25-2.0 D was detected in 24 (4.0%) persons and in 19 (3.1%) persons it was over 2 D.