Ocular surface vital dye staining is a measure of ocular surface damage and is frequently used as an endpoint in clinical studies. The identification and development of standardized objective outcome measures for the evaluation of therapeutic intervention of ocular surface disease is an area previously identified as critical to the future of well-designed clinical trials in this area. The Report of the NEI / Industry Workshop on Clinical Trials in Dry Eyes identified, the standardization of clinical tests used to diagnose dry eye states and assess treatment effects, as an area of critical interest. The purpose of this protocol is to determine the suitability of slit lamp biomicroscopic digital photography of ocular surface vital dye staining by comparing it to the current standard procedure, clinical assessment. Digital image-based assessment would have many advantages over current procedures and would apply the appropriate rigor to the evaluation of the anterior segment that has been shown to be an extremely effective method for the evaluation of the extent of posterior segment diseases such as diabetic retinopathy and age-related macular degeneration. Such valid, reproducible, reliable photographic documentation of retinal abnormalities and disease progression has been successfully employed as a primary outcome measure in many large clinical trials. In this protocol, we will compare grading of digital images of ocular surface staining to clinical assessment, facilitating the use of ocular surface vital dye staining as a valid outcome measure in clinical trials.