A single-case experimental analysis of the effects of ambient prism lenses for an adolescent with developmental disabilities.

We evaluated ambient prism lenses as an intervention to improve the cognitive and motor skills of an adolescent diagnosed with autism and mild mental retardation. Cognitive tasks were presented in both ambient prism lenses and no lenses conditions across four assessments in a multielement design. We then evaluated the effects of ambient prism lenses, placebo lenses, and no lenses on motor skills assessed in previous studies (i.e., balance beam walk and ball-catch) as well as leisure and vocational tasks relevant to the student's academic programming (i.e., money sorting and basketball shooting). Results across assessments indicated relative increases in scores across all experimental conditions, indicating practice effects. No differences across the use of ambient prism, placebo, or no lenses conditions were observed. We conclude with a discussion on how to objectively evaluate controversial and/or alternative therapies for children with developmental disabilities.