ObjectivesThis study aims to evaluate the effect of congenital ectopia lentis (CEL) on functional vision and eye-related quality of life (ER-QOL) in children and their families using the Paediatric Eye Questionnaire (PedEyeQ).DesignA questionnaire survey administered via in-person interviews of patients with CEL and their parents.Participants51 children with CEL and 53 visually normal controls accompanied by 1 parent completed the survey questionnaires for the study from March 2022 to September 2022.Outcome measuresPedEyeQ domain scores. Functional vision and ER-QOL of children and their families were evaluated by calculating and comparing the Rasch domain scores of the PedEyeQ.ResultsPedEyeQ domain scores were significantly worse with CEL compared with controls (p<0.01 for each), with the exception of the Proxy Social domain among children aged 0–4 years (p=0.283). Child PedEyeQ greatest differences were in the functional vision domain (5–11 years, −20 points (95% CI −27 to −12)) and frustration/worry domain (12–17 years, −41 (95% CI −37 to −6)). Proxy PedEyeQ greatest differences were in the functional vision domain (0–4 years, −34 (95% CI −45 to −22)) and frustration/worry domain (5–11 years, −27 (95% CI −39 to −14); 12–17 years, −37(95% CI (−48 to −26))). Parent PedEyeQ greatest difference was in the ‘worry about child’s eye condition’ (−57 (95% CI (−63 to −51))).ConclusionsIn this study, children with CEL had reduced functional vision and ER-QOL compared with controls. Parents of children with CEL also experience reduced quality of life.