Just give it a try: A single-subject multiple baseline study and a Delphi study to support individuals with moderate to profound intellectual disabilities to wear glasses

Individuals with visual impairments and intellectual disabilities (ID) often do not wear glasses, although this may improve functioning. We present (1) a single-subject multiple baseline study that examined the effects of wearing distance glasses on viewing behaviour, adaptive functioning, and well-being in a participant with severe ID, and (2) a Delphi study that examined the perspectives of 12 professionals on wearing glasses by individuals with ID. The participant adapted to wearing glasses with the Glasses Habituation Programme. Wearing glasses indoors decreased attention to objects further away, possibly because objects were recognised faster. Interviews with the caregiver and father showed that visual (related) behaviours improved, especially outdoors. Caregiver-reported questionnaires revealed better adaptive functioning but decreased well-being. Professionals identified key factors for the provision and successful wearing of glasses and agreed on the potential positive effects in different domains. Findings, if replicated in larger randomised controlled trials, point to the added value of glasses.