Related Experiment Videos
Cylindrical refractive error: a population study in western Newfoundland
Abstract:
The distribution of cylindrical refractive error (right eye only) is presented for 957 persons, comprising approximately 80% of the population (aged 5 years and over) of three western Newfoundland communities. In 72% of males and 60% of females no cylindrical error was found; 12% of males and 19% of females had errors greater than 0.5 D. Cylindrical errors of 2 D or greater were found in 2.5% of females of but only 0.5% of males, affecting females of all ages but males aged less than 15 years only. Persons aged 45 years and up had fewer cylindrical errors, more against-the-rule and less with-the-rule astigmatism than persons below that age. Cylindrical error and spherical error, and in particular against-the-rule error and myopia, commonly occurred together. Among persons aged 5 to 14 years an association of with-the-rule error with nearwork is suggested.