Flex Hinge Technology is a fantastic new technology that removes the need for screws. Now if you do not wear glasses you do not understand how fantastic it is to have the need for screws in your glasses removed. For one these screws have a tendency to break, which means you have to go to the store and buy one of those little kits to replace the screw. You hope beyond hope that you have the correct size screw, but you never do manage to find one that fits just right. Then when you get your glasses fixed with these generic one size fits all screws you have a good chance of stripping your glasses. At this point it is impossible to fix them and you either have to buy a new pair or put up with your broken pair. Plus if you break your glasses and have to fix them how are you going to do it? You wear glasses! You need to either find your spare pair or get a friend to fix them. The new durable Flex Hinge Technology removes all of these issues.