Figure 1.
A rectangular region labeled Tear lies above another rectangular region labeled Cornea, which is divided into multiple vertical sections representing corneal layers or compartments. A horizontal arrow on the left points from left to right into the tear layer and is labeled J subscript vL, J subscript sL. A horizontal arrow on the right points outward from the tear layer and is labeled J subscript vD, J subscript sD. A vertical upward arrow extends from the top of the tear layer and is labeled Jsubscript vE. Another vertical upward arrow originates at the tear–cornea interface and is labeled J subscript vC, J subscript sC. The diagram illustrates fluid and solute transport into the tear layer from the left, from the cornea below, evaporation from the tear surface, and outflow toward the right.
Schematic of the corneal epithelium and its adjacent tear. Volume and solute flows are designated and , in which α = L, C, E, and D refer to lacrimal gland, corneal cell, evaporation, and nasolacrimal flows.