Use of the acuity card method to test retarded children in special schools.

Acuity cards were used to measure the visual acuity of students at a special school for retarded children, including some who were profoundly retarded and spastic. Almost all children could be tested by two testers on each of two days, and the agreement between different tests was good for children with acuities better than 0.2. Children with poorer acuities had poorer agreement between different test results. High success rate in testing and generally good inter-test agreement indicate that acuity cards can be used in a special school setting to obtain information about the vision of retarded children, who are much more likely than other children to suffer from poor vision.