Journal of Cataract and Refract. Surgery:  Negative dysphotopsia is a mystery and can sometimes bother patients after excellent, routine phaco. They see a dark crescent in their temporal field. Theories like edge glare or certain lens materials have been suggested. In a small, retrospective study of operations to help these patients, a typical in-the-bag IOL exchange did not help. It seems what did help, was reverse optic capture-pushing the optic forward so that it lies in front of the capsulorhexis edge. To be honest, I don’t know why that should help, and hopefully, a better study will come out and finally put this issue to rest.