The bifocal glasses are mainly suitable for the elderly to use, and can achieve near and far vision. When people get old, their eyesight will decline and their eyes will become senile. And bifocal glasses can help the elderly to see far and see near.
The dual lens is also called bifocal lens, which mainly includes flat top lens, round top lens and invisible lens.
The lenses of bifocal glasses are required to include hyperopia diopter, myopia diopter or downlight. Distant pupillary distance, near pupillary distance.