“ A casual remark by one of the party about something met on a previous adventure leads to a summons to and grilling by the Mages' Guild (or equivalent), probably resulting in an expedition back to that area to recover the things for study by the Guild. The party's presence will be 'requested' for this expedition.”
“ A village where everyone goes blind sometime during puberty. What could be causing this? Perhaps something in their diet. Or some malignant gene. How would an entire village where only young childen can see function?”
“ Earrings are said to give the sailor better sight. The pulse center for the eyes is through the earlobe.”