In order to uncover the role of early astigmatism in
emmetropization and the development of refractive errors,
a longitudinal study beginning at birth and carried
out for a sufficient number of years is needed. Our
longitudinal study of refraction, begun 23 years ago,
now contains over 4000 refractions from children with
a first refraction in infancy and from 6 to 23 years of
regular follow-up. In this paper we confirm and extend
previous reports from this laboratory tracking changes
in refractive errors in children, with an emphasis on
astigmatism.