It's not central to the podcast, but the cornea is much much thicker than just 2 cells.
The cornea's thickness is around 570 μm, the epithelial layer on the surface is about 50μm (7+ cell layers). If I remember correctly it is the layer of collagen under the epithelial layer that when damaged causes a lot of the neovascularization and scarring associated with infections and mechanical damage, but that's remembering a primer from quite a long time ago.
Mon Apr 30 14:37:42 2012