VISION TESTING OF YOUNG-CHILDREN IN THE AGE RANGE 18 MONTHS TO 4 1/2 YEARS

Normal children (425) in the age range 18 mo. to 4.5 yr have been studied to determine the percentage of children according to age who can be expected to cooperate in a letter-matching vision test using a key card; to see whether the use of plastic letters to replace the key card lowers the age at which a letter-matching test can be achieved, and to show that children in this age range can do a vision test at 20 ft (6 m). Acceptance of occlusion using a patch occluder was also examined. The study shows that children effectively begin to cooperate in letter-matching vision tests using a key card from 33 mo. of age. Replacement of the key card with plastic letters lowers the age to 30 mo. and thereafter there is a gain of some 25% of children up to 39 mo. All children were successfully tested at 20 ft (6 m). The most difficult age for occlusion was in the age group around 2 yr.