According to aspects of the present disclosure, a kit for transepithelial delivery of a cross-linking agent to a cornea includes a first vessel containing an initial formulation that includes a cross-linking agent and a first active ingredient configured to open corneal epithelial tight junctions when applied to a cornea and one or more second vessels each containing a respective secondary formulation that includes the cross-linking agent for application to the cornea after the initial formulation is applied to the cornea.