The Knuckle Sandwich Multi Focus Spring Hinge Progressive Reading GlassesGive A Knuckle Sandwich In These Multifocal Lenses Multifocal readers perfect for the nerds who work out. Funny enough, these glasses will make it a breeze to read those tiny workout instructions, so you can finally stop making up excuses for skipping leg day. *The power you select is the magnification at the bottom of the lens and is 50% of the strength at the top of the lens. +1. 00=+. 50 +1. 50=+. 75 +2. 00=+1. 00 +2. 50=+1. 25 +3. 00=+1. 50