The astigmatic modulus and its age-dependence.
The question is posed as to why the modulus of the astigmatic vector appears to be randomly distributed with age. This paper investigates astigmatic population distributions. On the assumption of statistical independence, the expected probabilities are determined and compared with the observed values. Measures of central location are examined so as to determine skew distributions. A correlation is sought between the spherical and the astigmatic components of refractive corrections. It is concluded that the modulus is age-dependent but that the variations that occur across the age groups are smaller than can be measured by clinical routines.
D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging; D001251:Astigmatism; D002648:Child; D006801:Humans; D008875:Middle Aged