Examine the cornea and identify

• The surface epithelium,
• Bowman's membrane,
• The stroma or substantia propria,
• Descemet's membrane, and
• The endothelium (Fig. 23-4).

What epithelial cells are found in the cornea?

What type of collagen would predominate in Bowman’s and Descemet’s membranes?

What is the function of the corneal endothelium?

Clinical note: Corneal surgery to improve vision by changing the shape of the eye is now common. Making a radial arrangement of incisions into the stratified surface epithelium and stroma with a computer-guided scalpel, a process called radial keratotomy (RK), changes the shape of the cornea as the incisions heal. A newer procedure called laser in situ keratomileusis (LASIK) involves making a flap in the center of and partially through the cornea, using a computer-controlled beam of UV light to sculpt the underlying stroma, and repositioning the flap.

Last, let's look at the eyelid.