Illustrate the metabolism of cornea?

Metabolism of Cornea:

The corneal epithelium plays several roles in the process of image formation. Its apical cell border interacts with the tear matrix to obtain an optically smooth surface and extremely regular thickness. Corneal smoothness is evaluated with a Placido's disc. Tight packing of individual epithelial cells is by the many desmosomes. The scattering of light by the epithelial cells decreases the clarity of image. The process that leads to variation of refractive index within the epithelial cells decreases the clarity of image, for example, corneal edema either due to intraepithelial cell edema or intracellular edema. The common cause of intraepithelial cell edema is epithelial hypoxia resulting from contact lens over wear or intercellular edema may result from high IOP, as is seen in acute angle closure glaucoma.