RESUMO
Measurement of visual acuity in children is more difficult than in adults. Children tend to riet when the threshold is reached and become inattentive. However the exact determination of visual acuity in children is important in some situations (Screening, Amblyopia). In this paper we examined whether an automated procedure is more exact than measurement by an examiner. Three series of experiments were done. In n = 173 we measured visual acuity first by an examiner using an optotype projector and second by an automated procedure (computer, keyboard, television screen). Both, the examiner and the computer used the same test-procedure and threshold criterion (DIN-Norm). The correlation coefficient was 0.84. In n = 53 children (age 4 to 7) visual acuity was measured by an examiner without a special strategy. Afterwards visual acuity was measured by the automated procedure. The correlation coefficient was 0.1. In n = 63 children (age 5-7) visual acuity was measured by an examiner using a strategy and a threshold criterion. Afterwards the automated procedure was used. The correlation coefficient was 0.69. The results show, that without a strategy and defined threshold criterion it is not possible to compare the measurements of visual acuity in different times. An automated procedure presented in this paper guaranties constant test conditions in an optimal way.
