For the purposes of this study, active* ocular disease is defined as infection or inflammation which requires therapeutic treatment. Mild (i.e. not considered clinically relevant) lid abnormalities (blepharitis, meibomian gland dysfunction, papillae), corneal and conjunctival staining and dry eye are not considered active ocular disease. Neovascularization and corneal scars are the result of previous hypoxia, infection or inflammation and are therefore not active. Participants will be excluded with significant slit lamp findings (e.g. infiltrates or other slit lamp findings Grade 3 or above: corneal edema, tarsal abnormalities, and conjunctival injection) or active ocular disease (e.g. glaucoma, history of recurrent corneal erosions, and intraocular infection or inflammation of an allergic, bacterial, or viral etiology)