Half rim glasses are unique shape eyeglass frames where the top half is fixed in shape, and the bottom half is rimless. It is designed to allow some extra compensation for the eyeglass lenses at the bottom of the glasses. Most current half frame glasses have lenses that are fixed with clear fish wire links at the bottom, thus giving a more aesthetically pleasing appearance.
First, make sure that your lenses are the original lenses on your glasses and that the fishing line on top of the frame is not broken. Hold the top of the lens to the top of the frame with your fingers, and on top of that, use a small metal rod to pick up the fishing line and snap it into the groove of the lens from front to back with a little effort.
Compared to full-rim frames, half rim frames are more prone to damage. However, as long as you pay attention to the usual is no problem, but the half frame glasses are the more retro trend.