Eyeglasses fall apart
I don''t know about frameless glasses, but the main reason I''ve found for lenses falling out of framed glasses is that the lenses are not properly fit to the frames. When the lenses are ground too small for the frames, they have to be installed with a thin gasket around them, too prevent them from rattling in the frame opening. The gasket allows the frames to flex too much, and the screws back out. I don''t accept glasses that have a gasket around the lens, and I have no problem with the screws backing out or the lenses falling out. When there''s no space between the lenses and the frame, the lenses actually support the frame, and keep it from flexing.