Visual acuity in newborn and preterm infants measured with grating acuity cards.

Binocular visual acuity of normal newborn infants, preterm newborn infants, and newborn, full-term infant patients with nonophthalmologic abnormalities was measured by means of grating acuity cards. Each test took about six minutes to complete, and 89% of the tests (154 of 174) were successful. Visual acuity of infants at 39 to 40 weeks of gestational age was about 0.023 stripes per minute of arc, or 0.69 cycles per degree (20/866). Between 34 and 44 weeks of gestational age, visual acuity improved at the rate of 0.46 octaves per month. This test is simple, fast, and reliable, and requires no apparatus except the cards themselves.