The Status of School Vision Screening: A Review of Research and Consideration of Some Selected Problems.

The current view of the multidimensional nature of learning difficulties includes visual difficulties as one contributing factor. Although many researchers decry the use of the Snellen Test as the sole screening device, this test is still the most commonl y used vision screening instrument in our nation's schools. Findings of numerous studies comparing the accuracy of referral of various screening instruments to the findings of trained visual examiners are summarized. In general, the higher the rate of correct referrals, the higher also is a battery's tendency to overrefer pupils. The lower the number of correct referrals, the higher the tendency for underreferrals. The stereoscopic visual screening devices appear to overrefer, while the Snellen Test and the Massachusetts Vision Test tend to underrefer. A Modified Clinic Technique, requiring trained examiners and some technical equipment, has been identified as the most effective method in screening pupils for referral. Some factors influencing accuracy of referral are summarized. Commentaries on the general status of school visual screening programs are most often negative, and improvements are slow in coming. A bibliography is included. (CM)