Fig. 2

Development of the NEI VFQ-­28­-R. Items retained from the unchanged NEI VFQ-25, and items from the NEI VFQ-25 Appendix, are indicated by solid arrows. NEI VFQ-25 items excluded from the NEI VFQ-28-R are indicated by terminated lines. NEI VFQ-25 items that had their response levels modified (response levels combined or one level rescored as missing data) are indicated by dashed arrows