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200 pupils tested acute vision acuteness of vision alphabet test asked to step average distance ball best light close degree detected diameter different sized letters discern divided by 200 Dot test fairly constant feet and try feet variation figures grades graphs greatest distance illiterate cards largest number letter test letters and characters letters or characters letters or dots letters were seen limit of vision mean variation normal eye normal vision number of pupils obtained by tests operator percentages poor vision pupils saw representing the acuteness represents the results required to move Results obtained retina ring seen at 20 series of tests seven tests side of normal sixteen feet sixteen foot letters small squares Snellen 12 ft Snellen letters Snellen measurements subnormal table 11 tance tangent test for acuteness tests under consideration total combined distance twelve feet twenty-four feet vision as shown VISION OF SCHOOL vision showing