For example, among the drugs for glaucoma treatment, a major cause of legal blindness (Quigley and Broman, 2006), these are timolol metabolized by CYP2D6; betaxolol, a substrate for CYP1A2 and CYP2D6; dorzolamide eliminated by CYP2B1, CYP2C9, CYP2E1, and CYP3A2; and pilocarpine, which inhibits CYP2A6, CYP2A13, and CYP2E1 (Kimonen et al., 1995). Here, CYP2E1 is linked to glaucoma.