Asymptotic multifocal glasses are the upper optical area of the lens used to look far and the lower optical area used to look near. The degree of the middle gradually change, which used to look at the intermediate area.
We change the curvature of the lens surface from top to bottom, adding positive diopter, which result in the effect of visual correction.
Most people wear progressive multifocal glasses need about a week of adaptation, but the adaptation period varies from person to person, walk slower when feel dizzy.
