Infant astigmatism measured by photorefraction.
Photorefraction of a sample of 93 infants of ages 1 day to 12 months showed that 63 percent of the subjects had astigmatism of 0.75 diopter or greater, and 12 percent greater than 2 diopters. Seventy percent of these astigmatisms were in the horizontal-vertical meridians. By comparison, only 8 percent of a sample of 26 adults tested by the same method showed astigmatism (all 0.75 to 1 diopter). The high incidence of infant astigmatism has implications for critical periods in human visual development and for infant acuity.
D000328:Adult; D000367:Age Factors; D001251:Astigmatism / Q000175:diagnosis* / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000175:diagnosis*; D010781:Photography; D012029:Refraction, Ocular / Q000379:methods*