I believe there was a 1989 study/article by Groenveld and Jan that stated that subtest scaled scores (on visual portions of cognitive tests) vary with visual acuity. I may be wrong about the date or the authors, but if anyone has a reference for this, or something like it, please contact me. Carol -- Carol Evans, PhD Former TVI School Psychologist (Retired/Available for Consultation) *http://www.aph.org/accessible-tests/position-papers/intelligence-testing/full/ <http://www.aph.org/accessible-tests/position-papers/intelligence-testing/full/>* *http://www.myschoolpsychology.com/disability-information/visual-impairments/ <http://www.myschoolpsychology.com/disability-information/visual-impairments/>*