Glasses are also possible since facial shapes can be divided into straight and curved shapes. However, when distinguishing the types of lines in glasses, it is necessary first to understand the structure of the glasses.

According to the lines presented in these two parts, glasses are usually divided into five types: full frame; Borderless; Half border; Bull horn frame; browline edge crossbar frame.

Full frame refers to the frame completely covering the lens. The line type of the full frame is mainly determined by combining the frame and crossbeam. Half frame refers to the frame that directly wraps around a part of the lens. At present, there are very few glasses with crossbeams, and as people's requirements for shape become higher, it is not ruled out that such designs will be available in the future. If there is no crossbeam, the lines of the half frame are mainly determined by the frame of the upper part.

Borderless glasses naturally refer to glasses without frames. Compared to other glasses with frames, this type of glass has much weaker lines, and at this point, the shape and lines of the lens itself are the main focus.

Bull horn round tortoise shell glasses frame refers to a rectangular plastic frame that generally does not have a nose pad, or the nose pad is not obvious. This type of frame is generally thicker and has strong lines.

The browline edge crossbar frame refers to a crossbeam located in the middle of the eyebrows, presenting a double beam shape. The lines of this type of crossbeam also have a significant impact on the shape of the glasses.