Schematic of the human cornea identifying the epithelium, the anterior basement membrane, Bowman's layer, the stroma, Descemet's membrane and the endothelium. The elastic modulus of the anterior basement membrane and Descemet's membrane were determined by AFM to be 7.5 kPa and 50 kPa, respectively. Reprinted with permission from Last JA, Liliensiek SJ, Nealey PF, Murphy CJ. Determining the mechanical properties of human corneal basement membranes with atomic force microscopy. J Struct Biol. 2009;167:19–24. Copyright 2009 Elsevier.