PROTOTYPE AND TELLER ACUITY CARDS YIELD SIMILAR ACUITIES IN INFANTS AND YOUNG-CHILDREN DESPITE STIMULUS DIFFERENCES

1. The acuity card procedure allows rapid assessment of grating acuity in infants and young children. 2. Initially, prototype acuity cards were constructed with one aperture on the left and one on the right of the card. A high spatial frequency grating (the ''blank'' target) was located behind one aperture and a second grating, which varied in spatial frequency from card to card, was located behind the other. 3. In the commercially-produced Teller acuity cards, there is a single grating target located on one side of each card. It has been suggested that the single grating target may contain edge and brightness artifacts that lead to overestimation of acuity in infants and children. 4. If the stimulus configuration of the Teller cards does lead to overestimation of acuity, then the body of research conducted with the prototype cards to establish reliability and validity may not be applicable to acuity tests conducted with the Teller cards. 5. We conducted a within-subject, within-tester comparison of prototype vs Teller card acuities in 20 4-month-old, 20 12-month-old, and 20 36-month-old healthy preterm children. 6. Monocular acuity of each child's right eye was tested once with each card type by a single tester who was masked to the grating spatial frequency of each card. 7. Paired t-tests showed no differences between acuities obtained with the two card types at any age. 8. Thus, stimulus differences (including possible edge and brightness artifacts) between prototype and Teller acuity cards do not result in overestimation of acuity in infants and young children 4-36 months of age.