A Computerized Grating Visual Acuity Test for Impaired Children

Abstract

Twenty developmentally delayed or neurologically impaired children, aged 3 to 11 years, were referred for visual acuity assessment. None could be tested with Snellen letters, illiterate E's, or Allen pictures. All were beyond the age at which standard preferential looking techniques are considered to be effective.

Our method, in which children learn to point to grating stimuli, enabled us to obtain monocular visual acuity estimates in 16 of the 20 patients (80%). Mean dominant eye acuity in this group (20/70) is comparable to that previously reported in a similar series (20/73), before computerization of the test procedure. When indicated, patching therapy was begun and was monitored with this method. We consider this a clinically useful test of visual acuity in nonverbal impaired children.

• vision
• preferential looking
• amblyopia