Background: Vision-related quality of life is an important endpoint for evaluation studies and quality assurance projects. The objective of this study is to conduct a psychometric test of the German version of the "Children's Visual Function Questionnaire" (FKS) in the version for children over age 3.
Methods: In a sample of n=236 children with various eye diseases distribution properties, internal consistency, unidimensionality, validity, and the fit of the FKS data to the Rasch model are tested. In addition, reference values are given for users.
Results: The FKS has satisfactory internal consistency and is valid in the sense that expected significant correlations occur with visual acuity. The weakness of the FKS, which provides impulses for further development, is primarily related to the scales for competence and personality in the following three areas: (1) high percentage of inapplicable questions, (2) ceiling effects, and (3) lack of unidimensionality.
Conclusions: Overall, the FKS satisfactorily complies with psychometric standards. Therefore, it can be applied to assess children's vision-related quality of life.