The practice and principle of eyeglasses

Eyeglasses are made of optical resin, which is a high polymer material (commonly known as plastic) with high light transmittance and strong refractive index, which is made into a lens to utilize the principle of optical imaging and made into eyeglasses.

Of course, the polymer is divided into soft and hard, hydrophilic, breathable, and can be divided into contact and non-contact lenses.

In the past, eyeglasses were lenses with one or two focal lengths, but nowadays, due to the change of processing technology, they can be made into multifocal lenses, also known as progressive lenses, which are more convenient for people with deep myopia and hyperopia.