Background: There is a relative lack of information on the incidence and treatment of vision problems in Prader-Willi syndrome (PWS). Using data from the Global PWS Registry, we performed a cross-sectional study of vision problems in PWS. Methods: Data, reported by caregivers who completed the Vision Survey in the Global PWS Registry between May of 2015 and March of 2020, were analyzed using descriptive statistics. Results: There were 908 participants in this survey, with a mean age of 14.5 years (range 0–62 years). The prevalence of strabismus in this population was 40 %, with no statistically significant difference in prevalence by genetic subtype. Ninety-one percent of participants with strabismus were diagnosed before 5 years of age. Of those with strabismus, 42 % went on to have strabismus surgery, with 86 % of those having their first strabismus surgery before 5 years of age and 10.1 % having more than one strabismus surgery. Additional vision issues reported included myopia (41 %), hyperopia (25 %), astigmatism (25 %), and amblyopia (16 %). Conclusions: The prevalence of strabismus, amblyopia, and hyperopia are considerably higher in the PWS population represented in the Global PWS Registry as compared to the general population. People with PWS should be screened early and regularly for vision problems.