Given that detailed or locally oriented perception is a central tenet of visual cognition in autism (Behrmann, Thomas, & Humphreys, 2006; Dakin & Frith, 2005; Mottron, Dawson, Soulieres, Hubert, & Burack, 2006), several studies have systematically assessed the spatial resolution of vision in autism by measuring visual acuity (VA). VA is generally defined as the ability to perceive targets such as optotypes, letters, or numbers of a specific size at a given distance. For example, “normal” Snellen VA, often referred to as 20/20 vision, is a clinical term that reflects a person’s ability to recognize a target (i.e., letter E) from 20 ft away when its defining spatial features (i.e., spacing of lines composing an E target) are separated by a visual angle of 1 arc minute.
Several studies have assessed VA in ASD using a variety of clinical screening charts. For the most part, VA has been demonstrated to be unremarkable in ASD when assessed with either the Crowded LogMAR test...