Metabolic stress occurs at disease onset and causes altered flavoprotein redox activity that increases flavoprotein autofluorescence (FA). Using a new method to measure ocular FA, we studied women with subtle visual dysfunction due to pseudotumor cerebri. Each FA value was greater in the more affected eye of each woman with pseudotumor cerebri, permitting identification of that eye in each case. Flavoprotein autofluorescence values averaged 60% greater in more affected eyes of women with pseudotumor cerebri, but not between eyes of healthy women (control subjects). These results demonstrate the clinical utility of FA and may permit early detection and monitoring of retinal and optic nerve diseases.