ABSTRACT
Vision Screening of 1211 preschool children at 6-year-old was done by the visual acuty test, the cover test, and the stereoacuity test primarily. Secondarily, the corrected visual acuity, the refractive state. the amount of ocular deviation, and the cause of amblyopia were evaluated if the monocular acuity was 0.6 or less, or the difference of two or more lines on the Han's chart between right and left eye with the best optical correction was present, or the strabismus was detected on the primary screening. One hundred and thirty-eight children(11.4%) were abnormal on the primary screening. Seventy-nine children showed myopia. 46 hyperopia, and 3 alisometropia with the cycloplegic refraction, and 79 children also had astigmatism. Twelve children showed strabismus with the cover test. Among those, 8 belonged to exotropia and 4 to esotropia. Six children showed amblyopia and the causes of amblyopia were astigmatism, exotropla, and anisometropia. Among these 6 amblyops, 3 showed abnormal findings with the cover test and 2 showed stereocuity over 1200 seconds of arc. Therfore, among these three tests as primary vision screening, the cover test and the stereoacuity test to be inadequate to detect the amblyopia.