A Close Eye on the Eagle-Eyed Visual Acuity Hypothesis of Autism

Autism spectrum disorders (ASD) have been associated with sensory hypersensitivity. A recent study reported visual acuity (VA) in ASD in the region reported for birds of prey. The validity of the results was subsequently doubted. This study examined VA in 34 individuals with ASD, 16 with schizophrenia (SCH), and 26 typically developing (TYP). Participants with ASD did not show higher VA than those with SCH and TYP. There were no substantial correlations of VA with clinical severity in ASD or SCH. This study could not confirm the eagle-eyed acuity hypothesis of ASD, or find evidence for a connection of VA and clinical phenotypes. Research needs to further address the origins and circumstances associated with altered sensory or perceptual processing in ASD

Brief Report: Visual Acuity in Children with Autism Spectrum Disorders

Recently, there has been heightened interest in suggestions of enhanced visual acuity in autism spectrum disorders (ASD) which was sparked by evidence that was later accepted to be methodologically flawed. However, a recent study that claimed children with ASD have enhanced visual acuity (Brosnan et al. in J Autism Dev Disord 42:2491–2497, 2012) repeated a critical methodological flaw by using an inappropriate viewing distance fora computerised acuity test, placing the findings in doubt. We examined visual acuity in 31 children with ASD and 33controls using the 2 m 2000 Series Revised Early Treatment Diabetic Retinopathy Study chart placed at twice the conventional distance to better evaluate possible enhanced acuity. Children with ASD did not demonstrate superior acuity. The current findings strengthen the argument that reports of enhanced acuity in ASD are due to methodological flaws and challenges the reported association between visual acuity and systemising type behaviours