MNK4422 Ultra Sharp Nano Diamond Knife – 2.2 mm Clear Cornea 70°, Angled MountClear Cornea Ultra Sharp Nano Diamond Knife 2. 2 mm The Clear Cornea Ultra Sharp Nano Diamond Knife 2. 2 mm is a reusable ophthalmic microsurgical knife designed for creating a precise 2. 2 mm clear corneal main incision during phacoemulsification cataract surgery, IOL implantation, and anterior segment procedures. Manufactured in Switzerland, this advanced nano diamond knife combines a nano crystalline diamond cutting edge with a silicon scalpel