The use of the logistic curve to represent the prevalence of defective vision among persons of specific ages above 30 years
Collins, S.D.; Pennell, E.H.
Human Biology 7(2): 257-266
1935
ISSN/ISBN: 0018-7143 DOI: 10.2307/41447655Document Number: 198844
The Pearl-Reed logistic curve was fitted to data on the % of malemale and femalefemale with defective vision (any degree, either eye) at specific ages from 30 yrs. to the end of life. This curve apparently gives a good description of the growth of presbyopia in the population during these ages. From the curve there is computed the number of new cases of defective vision per 1,000 persons at each year of age. Presbyopia appears to come earlier in femalefemale than in malemale. The peak of the curve of the incidence of new cases of defective vision comes at 40 years in femalefemale and at 44 in malemale.