How are glasses
Glasses are a useful tool in combating those with visual impairments such as myopia. Of course, many individuals opted to use contact lenses to correct their vision but these are not ideal for everyone and many people find them to be uncomfortable. Glasses consist of the frame and two lenses, and the frames are most commonly made from either cellulose acetate, which is a type of plastic or from raw metals. The most common form of frame is made from cellulose acetate, which is a derivative of cotton and is extremely durable while providing flexibility. Cellulose acetate is manufactured in narrow and long sheets that are designed to be a little bit wider than the frames of the glasses. In fact, these sheets are produced of up to 3 feet and can be almost 1 cm thick.
There are several methods used for producing glasses frames, and the most popular is die cutting. Once the final design has been put in place, a die is created from steel and placed into a blanking machine. The planking machine then punches the cellulose acetate to cut out the frame design. Before going through the blanking, the sheets of cellulose acetate are heated to roughly 68 degrees Celsius to help create a softer plastic. This is then placed in the machine which comes down on it with a pressure of several tons. Once the frame has been cut, it will go through a process of being cut using a router. This cuts grooves into the frame for the lenses to be clicked.
The frames then undergo a process that smoothes out any rough edges, before the nose pads are attached with a glue. The glue is then left to set for roughly 24 hours before the rough edges are smoothed out. After this, the temples are attached to the frame, where small slots are cut into the frame itself and a hinge is attached. The temples are then affixed to the hinge and allow for an open and closing motion. Finally, the completed set of glasses goes for inspection to check for quality and defects. The entire process of completing one set of glasses frames takes an average of 48 hours from start to finish. Once the frames have passed quality control, they are then placed into a case and sent to the Opticians for the customer. A similar process is used for frames that are made from metal, only these well typically use lasers to help soften any rough edges.