There are many kinds of glasses, which can adjust the amount of light entering the eyes, correct vision, protect eye safety and treat eye diseases in clinic. The function of glasses frame is not only to form a supporting frame for glasses worn on people's eyes, but also to have beauty and decoration functions.
The early frame materials were mainly metal and tortoise shell, including stainless steel, titanium, copper, plastic, Monel, nickel alloy and so on. Glasses with memory alloy frames can keep their shape even if they are flexed, and will not break, so that the life of glasses is longer and the inconvenience caused by broken frames is avoided. Adding a spring to the hinge of the frame arm also makes the glasses more durable. The frame made of titanium is lighter and more corrosion-resistant, which avoids the corrosion of sweat to the metal during long-term wearing and loses its luster. There are also many kinds of glasses lenses, which can be mainly divided into two categories: glass lenses and optical resin lenses. Resin lenses are generally much lighter than glass lenses and have better impact resistance than glass sheets, but their surface hardness is low and they are easy to be scratched.