An analysis of visual defects among 310 children referred from a vision screening of 2 178 7-year-old children revealed a 50% frequency of significant eye defects among the referrals (7% of screened children). Of the screened children, one group (1 530 children) had previous visual screening three years earlier. The other group (648 children) had no previous vision screening until the age of seven. A comparison between the two groups showed that the risk of finding a new significant eye disorder in a school entrant was more than 6 times greater for a child who was not examined in his preschool years, and the risk of finding an amblyopic child was more than 10 times greater. The results do indicate the need for continuation of the present vision screening program of pre-school children.