You can get it from your contact lens solution.
Y'all are pussies. I have permanent stigmata scabs in the bony notch where the top of the foot meets the ankle - the result of 15 years of combat boot stupidity. Plus the sides and bottoms of my feet are calloused like dried and salted fish. Add some ever-changing mottled bruises and blisters and you have a podiatrist's nightmare.Actually, with all this foot damage, maybe I should start worrying about diabetes. ;-)JG