PURPOSE:To describe a standardized technique for acquiring and viewing photographic images of eyelids, assess the reproducibility and validity of a grading protocol for signs of anterior blepharitis, and to explore whether the signs depend on the eyelid or the area of the eyelid assessed. METHODS:Subjects with anterior blepharitis ranging from none to severe were examined by ophthalmologists at clinical sites. Digital images of the eyelids of subjects were acquired using a protocol that allowed for the calibration of color and luminance. Three ophthalmologists at a centralized reading center applied a novel protocol for grading features of anterior blepharitis from the digital images viewed on color-calibrated monitors. The agreement among graders was assessed using percent agreement and weighted kappa statistics (Kw), and the correlation of photographic and clinical gradings was assessed using Spearman correlation coefficients. RESULTS:Agreement among graders was excellent (Kw > 0.80) on the number of eyelid margin vessels and was substantial (Kw between 0.61 and 0.80) for erythema, collarettes, number of engorged vessels, and number of lashes. Grading of the photographic images and the clinical assessments of erythema and lid debris were moderately correlated (r = 0.27-0.45). The grades for different features depended on whether the upper or lower eyelid, eyelid skin or lid margin, and central or lateral lid were assessed. CONCLUSIONS:The application of a protocol to obtain and display calibrated digital images of eyelids supports the standardized assessment of anterior blepharitis in clinical care and research studies.