The corneal stroma is fibrous, tough, unyielding, and perfectly transparent inner layer of the cornea. It consists of about 200 flattened plates of collagen fibrils called lamellæ, superimposed one on another. They are each about 1.5-2.5 micrometres in thickness. These fibrils run at different angles and frequently interweave, the anterior lamellæ interweaving more than posterior lamellæ. The fibres of each lamella are parallel with one another, but at right angles to those of adjacent lamellæ. The lamellæ are produced by keratocytes, which occupy about 10 % of corneal stroma.