I packed these lightweight, durable, compact, and excellently protected in their hard case, glasses during my entire Appalachian Trail thru-hike. I whipped them out whenever I needed to read the fine print! Most glasses are bulky or heavy or too fragile for the trail. I highly recommend them, and their key selling point is that they are both retractable and folding. I only wish there were more styles in these, and that even optometrists sold them so I could get them to fix other vision problems other than simple magnification. Am buying a second pair.THANKSGreat Product. Comfortable yet portable. Easy to use. Will buy againTcan't believe these are out of stock on amazon! They just got some at the local Walgreens, i got the only 2.0 left, & was looking for another pair. These are the best glasses Ive had in years! The frames are extremely light, & they gently grip, so they don't fall off if you need to look down! In fact you can use them without extending the earpieces if you need to, 7 they'll stay on!They"re not flimsy either, yet they fold up to fit into a tiny but sturdy included hard case which is about the size of a lighter!!Also, my face is hard to fit glasses, because of nose broken several times as a teenager, yet these fit perfectly with no adjustment. Actually the only glasses I can remember that the nose piece hasn't become uncomfortable after a bit. I think this has something to do with the way it's designed to fold up so compactly, which makes them ever so slightly asymetrical, though it's not noticeable unless you study them really, really cloasely..Whoever designed these awesome frames should be selling them to optometrists! I'd love it if prescription glasses could be had in these!