STUDIES ON DEVELOPMENT OF VISUAL-ACUITY IN INFANTS MEASURED BY THE TELLER ACUITY CARDS

In order to confirm the reproducibility of visual acuity measurements in infants and to elucidate the cause of the plateau and decrease in the developmental curve between the ages of 9 and 15 months, we have retrospectively studied visual acuity measured by the Teller Acuity Cards (TAC) in infants aged 2 to 28 months. The visual acuity measured by TAC was higher than that obtained by the conventional preferential looking (PL) method in infants until the age of 14 months. No statistically significant difference was observed between the first eye and the second (fellow) eye measurements. Although monocular visual acuity decreased in infants aged from 9 to 12 months, binocular visual acuity showed an increase in the same age group. The first binocular measurement was better than the last binocular measurement on the same day. Although the first binocular measurement showed an increase in infants aged from 9 to 15 months, the second binocular measurement decreased in the same age group. Our results suggest that all these phenomena mentioned above are likely to be due to the psychological or behavioral rejection to the examinations.