Progressive Lens - Multifocal Lenses
Multifocal Lenses
Many people think that when they are older, when presbyopia begins to appear, myopia disappears. But more often, myopia and presbyopia appear at the same time as they get older.
In the past, both myopia and presbyopia had to wear bifocal lenses for correction. A clear line in the middle of the bifocal lens separates the upper and lower areas of the lens with different powers. Look straight ahead to see distant objects clearly, and see close objects clearly through the bottom of the lens. But when the line of sight passes through the dividing line, it will start "jumping" from two very different degrees and it feels bad to use.
Progressive Lenses
The progressive lens has no obvious dividing line, and the lens power slowly changes from bottom to top. Note! Because the diopter between the two powers will gradually change, the first-time wearer may feel uncomfortable and get used to judging the distance again. After a short adaptation period, the wearer will feel the benefits of progressive lenses.
Equipped with progressive lenses, no matter whether you look at the distant scenes or the near scenes, you will be satisfied and effortless. Progressive lenses are generally used to correct myopia and presbyopia, and white-collar workers who do long-term paperwork will wear them at work.
Corridor of progressive lenses
The progressive lens will have a "corridor", that is, the area from the telephoto side to the near side. This corridor has different lengths (11mm-17mm) to match the usage habits of different guests and the size of the frame. If it is equipped with progressive lenses, the frame needs to have a certain height, about 3cm~4cm to accommodate two different power areas.
ADD of progressive lens
In the prescription of optometry, the second degree of progressive lens will be expressed as "ADD", that is, the degree of seeing close objects. Depending on usage habits, 100 degrees - 250 degrees will generally be added.
