Purpose Eye pathology could be related to atypical visual behaviours and impaired social communication through visual cues in children with autism spectrum disorder (ASD). The main purpose of this prospective study was to assess ophthalmological disorders in children with ASD and to investigate the relationships with intellectual disability (ID) and ASD severity. Methods In this prospective study, comprehensive ophthalmological and oculomotor examinations were performed. ASD severity and verbal and performance intelligence quotients were determined using adapted scales. These clinical data were compared between groups of children based on the presence or absence of ophthalmological disorders and the achievement or not of visual acuity (VA) testing by using non-parametric statistical tests. Results Amongst a sample of 51 children, ophthalmological disorders were found in 39% of cases, with 35% having significant refractive errors and 10% presenting with strabismus. Children with ASD and ophthalmological disorders had significantly lower verbal (29.8 +/- 14.7 compared with 44.3 +/- 21.5; p = 0.010) and performance quotients (57.8 +/- 18.3 compared with 67.59 +/- 20; p = 0.049) but no significant result was found between the presence of ophthalmological disorders and ASD severity, level of communication and social contact, or modulating behaviour when changes occur. Children who did not achieve monocular VA testing (39%) had significantly lower verbal (25.1 +/- 9.7 compared with 46.1 +/- 20.9; p < 0.001) and performance quotients (52.7 +/- 17 compared with 69.8 +/- 18.8; p = 0.001), also presented higher social interaction impairment (p = 0.002), and expressed more important behavioural signs (p = 0.007). Conclusions Ophthalmological disorders are frequently found in children with ASD, especially in those with ID. Ophthalmologists and child psychiatrists should pay attention to perform ophthalmological examination in children with ASD since eye disorders might remain undetected. A comprehensive examination by a paediatric ophthalmologist would help to improve the individual clinical description and the global intervention.