Use MIXED LENSES Option if you Need Different Strengths in the Right and Left Eye *** This High Quality RX Optical Prescription Swim Goggles by View are completely assembled by 101Bestbuys for you! ***Super anti-fog treatment – 100% U.V. protection***Includes 3 Nose bridges – Medium Size is installed***If different strength lenses are needed on left and right side select MIXED STRENGTHS and enter available diopters only. If you are unsure which diopter to select, please feel free to send us a message with a copy of your prescription attached. We will get back to you with the correct lens strength to order. ***Smoke(black/gray) Goggles*** MIXED STRENGTHS are available in the following diopters only: +4.0, +3.5, +3.0, +2.5, +2.0, 0.0, -2.0, -2.5, -3.0, -3.5, -4.0, -4.5, -5.0, -5.5, -6.0, -6.5, -7.0, -8.0, -9.0, -10.0. We reserve the right to round down to the next .5 increment if an incorrect lens strength is entered.