Liberty sport rs z8 y-20 active eyewear information sizing: kids onlysee more help tab for eyesize information. Size: a b ed dbl tl 50 36.4 50.2 16 125 Available with non-prescription lenses for protection only in clear with silver mirror. Also available with amber brown or gray with silver mirror lenses by special order. No lens option is for prescription lens insertion only prescription lenses are an add on . Glasses cannot be worn without lenses. Available with prescription. Prices quoted for prescription are for prescriptions - 4.00 Sphere diopters with up to - 2.00 Cylinder. For additional lens options including anti-reflective coatings and tints, see prescription information page. Unisex shape. Nylo-flex material is virtually indestructible for ultimate ruggedness, flexibility and memory shockblok absorbs and transfers shock from the lens to the flexible frame 3d contour grip wrap temple and tpr nose pad gives a custom fit for all day comfort hypoallergenic material comes with semi-rigid case lifetime warranty *not certified to be used as protective eyewar. Liberty sport prescription information prescription lifetime warranty including scratched lenses you must register your product at liberty sport website. If you do not register at the time of purchase, the there will only be a warranty on the frame, not the prescription lenses. However, since these are manufacturer direct lenses, there is no exchange on these. Please make sure you are ordering the correct size. U...