ABSTRACT
A vision screening program was established at a regional center for individuals with severe or profound mental retardation. The visual acuity measure used was the acuity card procedure, a type of forced-choice preferential looking. Acuity values were evaluated in terms of test-retest reliability as well as inter- and intraobserver reliability. Acuity results compared favorably to those obtained in less compromised populations, and we conclude that the acuity card procedure is a useful screening tool for this population. Suggestions for its application in evaluating functional vision were also discussed.
Subject(s)
Education of Intellectually Disabled , Intellectual Disability/psychology , Vision Screening/psychology , Adolescent , Adult , Child , Child, Preschool , Female , Humans , Infant , Male , Middle Aged , Vision, Binocular , Vision, MonocularABSTRACT
We are studying infant rhesus monkeys that have been reared under various conditions of deprivation to model infantile unilateral aphakia. Grating acuity was assessed in these monkeys from birth to approximately 1 year of age using the quick acuity card procedure. We found that an uncorrected aphakic eye develops little or no pattern vision. Undercorrection or near point optical correction of an aphakic eye with an extended-wear contact lens coupled with continuous occlusion of the opposite eye sometimes results in normal development of acuity in the aphakic eye but does so only at the cost of loss of vision in the occluded eye. Fifty percent partial occlusion coupled with near-point correction of the aphakic eye results in similar development of acuity for both eyes during the time tested. Monkeys wearing near-point correction in the aphakic eye and without any occlusion of the other eye show surprisingly good residual acuities in their aphakic eyes. Based on these results we conclude that aphakic eyes should be treated by providing them with an optical correction, and that occlusion of the opposite eye should be used cautiously.
