Ashwin E, Ashwin C, Rhydderch D, Howells J, Baron-Cohen S. (2009) Eagle-eyed visual acuity: an experimental investigation of enhanced perception in autism. Biological Psychiatry. 2009 Jan 1;65(1):17-21. Epub 2008 Jul 23.
["Individuals with ASC have significantly better visual acuity (20:7) compared with control subjects (20:13)—acuity so superior that it lies in the region reported for birds of prey."]
Crewther DP, Sutherland A (2009) The more he looked inside, the more piglet wasn't there: is autism really blessed with visual hyperacuity? Biological Psychiatry. 2009 Nov 15;66(10):e21-2. Epub 2009 Jun 27.
[Correspondence. "Thus, the estimates gained for both ASD and normal individuals were all extrapolations beyond the range of acuity value testable with that viewing distance." "The main conclusion of Ashwin et al., that the foveal cone density is higher...also does not bear up in comparison with the hawk eye....Thus, it seems that in nature, greater resolution is achieved by greater eyeball size,... than by closer packing. It is clear that the eyes of autistic individuals are not twice as large as normal." "It is possible that the large number of trials might have contributed to concentration lapses in the control subjects, widening the gap in this extrapolated estimation of acuity between normal subjects and autistic subjects."]
Bach, M. Dakin, SC (2009) Regarding "Eagle-eyed visual acuity: an experimental investigation of enhanced perception in autism". Biological Psychiatry. 2009 Nov 15;66(10):e19-20. Epub 2009 Jul 3.
[Correspondence. "Prompted by the highly counterintuitive nature of both these conclusions and the finding that inspired them, we have investigated the procedure employed by the authors of this study....We report that although there are real behavioural differences between ASD and control groups, technical limitations in the procedure used to measure acuity call into question the conclusion that people with ASD have higher visual acuity compared with unaffected individuals without the context of the experiment."]
Ashwin E, Ashwin C, Tavassoli T, Chakrabarti B, Baron-Cohen S. (2009) Eagle-eyed visual acuity in autism. Biological Psychiatry. 2009 Nov 15;66(10) e23-4. Epub 2009 Jul 3
[Correspondence. "We accept that the technical issues outlined in the commentary need to be resolved."]
Kéïta, Luc, Mottron, Laurent and Bertone, Armando (2010) Far visual acuity is unremarkable in autism: Do we need to focus on crowding? Autism Research. Vol 3 Issue 6 p.333-341 December 2010. Article first published online: 6 OCT 2010 DOI: 10.1002/aur.164
["...the expected crowding effect at one gap-size opening distance was evidenced for the control group only.....These results suggest that although far visual acuity is unremarkable in autism, altered local lateral connectivity within early perceptual areas underlying spatial information processing in autism is atypical."]
Bölte S, Schlitt S, Gapp V, Hainz D, Schirman S, Poustka F, Weber B, Freitag C, Ciaramidaro A, Walter H. (2011) A Close Eye on the Eagle-Eyed Visual Acuity Hypothesis of Autism. Journal of Autism and Developmental Disorders. 2011 Jun 10. [Epub ahead of print]
["This study could not confirm the eagle-eyed acuity hypothesis of ASD, or find evidence for a connection of VA and clinical phenotypes."]
Tavassoli T, Latham K, Bach M, Dakin SC, Baron-Cohen S. (2011) Psychophysical measures of visual acuity in autism spectrum conditions. Vision Research. 2011 Jun 16. [Epub ahead of print] http://www.ncbi.nlm.nih.gov/pubmed/21704058
["Best corrected VA was significantly better than the initial habitual acuity in both groups, but adults with and without ASC did not differ on ETDRS or FrACT binocular VA." "We conclude that there is no experimental evidence for superior visual acuity in ASC."]
Marita Falkmer, Geoffrey W. Stuart, Henrik Danielsson, Staffan Bram, Mikael Lönebrink and Torbjörn Falkmer (2011) Visual Acuity in Adults with Asperger’s Syndrome: No Evidence for “Eagle-Eyed” Vision. Biological Psychiatry. In Press, Corrected Proof. Available online 31 August 2011. doi:10.1016/j.biopsych.2011.07.025