Progressive Addition Lens – The Most Fashionable Lens

progressive Addition Lens (PAL), which is known as progressive lenses, multifocal lens which is intended for those who have experience presbyopia. This type of lens is a development from bifocal and trifocal, which previously has become mainstay most of presbyopia.

As bifocal and trifocal lens, progressive lens also has a part to see far and near object. In addition, this lens also has a section called the local or regional aberration astigmatic (located on the right and left on the top of the lens), which may cause inconvenience, especially if the lenses are not appropriate. Therefore, glasses services need progressive knowledge and skills enough. This is different from bifocal lens and trifocal that does not have local or regional astigmatic aberration, so unmatched tolerance in the installation is high. Small error installation of bifocal lens is easily accepted by users.

Then, what the advantages provided by progressive lens as compensation on the part that does not make it? In the progressive lens, the part of long distance and least distance vision does not has extreme separate, so the firm emerged as the divider is shown in the bifocal lens and trifocal, but it is gradual separated. Separation on this area (called a progressive area) consists of several bowline made without the wrinkling line, a gradually curve increasing to the bottom (towards the near distance vision). The changes of gradually curve will produce dioptri power that also gradually changes, down to the more positive lens.

The result is, the progressive will provide a smooth transition of vision and sharpness when to see much closer view. This means by using this progressive lens, presbyopia patients will still be able to see a middle-distance area (between 5 to 0.5 meters from the eye) with a permanent clear. It’s different with the bifocal lens that only to be able to see far and near distance (30 - 40cm) only, while the middle distance will be relatively vague. If the lens is trifocal, it can be used to see the middle distance, but the sharpness of the maximum will only be available at the appropriate focus dioptri in the middle.

One thing the advantage of progressive lenses, you can not see dividing line between near vision and long distance vision of the lens, then it will be seen as a single focus lens, users have not yet seen as presbyopia (which is experienced at the age of 40).