Children should have their eyes tested before entering Grade 1 and then annually thereafter. We need to ensure that our children have 20/20 Vision so that their education is not compromised.
Children are naturally farsighted until the age of about 6, until which time their eyes should be fully developed. Some kids take longer however, and then feel strain with near work and computers etc. If you feel that your child has a problem with his vision before the age of 6, then please have them tested. The earlier you detect this, the better the prognosis.