Autism spectrum disorder (ASD) is a neurodevelopmental condition with a reported prevalence of one in 100. Currently there is a paucity of literature describing fundamental visual process in children with ASD making evidence-based clinical management difficult for eye care professionals. Methods This study aimed to describe the impact of ASD on the visual system by investigation of visual measures in 131 children with ASD and 206 age-matched typically developing children. Visual measures assessed included visual acuity, refractive error, ocular posture and binocular functions. A second aim of the study was to investigate current eye care services for children with ASD in Northern Ireland. A qualitative study investigated opinions, attitudes and experiences of parents of children with ASD and professionals providing eye care services for children with ASD in Northern Ireland. Results and Conclusions Review of the questionnaires identified several key themes including the need for improved communication, better facilities, reduced waiting times and improved awareness of ASD. Assessment of vision and visual function identified: • No significant difference in visual acuity between the ASD and control group • Significantly greater magnitude of refractive astigmatism in the ASD group • A significantly higher prevalence of heterotropia in the ASD group • Significantly, but not clinically, reduced convergence and stereoacuity in the ASD group • A significantly higher prevalence of accommodative dysfunction in the ASD group. • Participants with ASD demonstrated a greater reduction in accommodative responses when blur was removed compared to the removal of disparity. • Investigation of CVI suggested that a sub-group of participants with ASD may have dorsal stream dysfunction . • Investigation of retinal thickness identified a trend towards a slightly thicker retina in participants with ASD.