PPG Material Clear Vision 1.499 Sv Cr 39 Lenses , Bifocal Reading Glasses Lenses

Clear Vision 1.499 CR-39 No Coating Round Top Bifocal Lens For Reading Glasses
 
I. Specifications:

II. Round Top Bifocals:

You focus through different prescriptions at different distances through the same lens - hence the name. Bifocals (meaning a lens with two points of focus - usually one for distance and one for near) are the most commonly prescribed multifocal lenses.

Bifocal the upper part of the lens is generally used for distance vision, while the lower part is used for near vision. Usually, a segment line separates the two.

Typically a person with myopia would have one section of a prescription lens that has a certain diverging power while another section of the lens would havea lower diverging power for close-up work. Similarly a person with hyperopia would have one section of the lens with a certain converging power and another section with a greater power for close-up work.

Bifocal sare typically placed so the line rests at the same height as the wearer's lower eyelid. As a bifocal wearer drops his eyes downward to read, the eyes naturally seek out the near-vision portion of the lens.

• Who Need Round Top Bifocal Lens?

1. A salesman, who has mostly outdoor work and very little reading to do, would have a small round-top bifocal fitted.
2. An office worker, who has to deal with close work but still has a fair deal of distance activity would use a regular medium-sized round-top bifocal segment.
3. An executive who deals mainly with paper work or an accountant who has masses of figures to pore over would require either a very wide round-top bifocal or preferably the straight-line executive bifocal. However, do remember that though the straight-line executive lenses are excellent for desk work they cause problems when one has to walk with them, as the complete lower field is affected. Ideally, they should be left on the desk after finishing work and a smaller D or flat-top bifocal used for activities outside.

In an effort to decrease the chromatic changes and the object jump which are problems with fused bifocals, flat-top solid bifocals have been made. They have the advantage of lowered chromatic change and of no jump or no shift in the objects when the gaze is shifted from distance to near.

III. Technical Data:

IV. Packing&Shipping:

V. Why Choose Us:

Our Factory: Jiangsu Aogang Optical Glasses Co.,Ltd is a professional optical lens manufacturer for more than 10 years in China. All lenses are exported to European countries, Japan, Korea, North and South America, Middle East, Southeast Asia and Africa market. We guarantee the quality to all buyers all over the world, and got a high reputation about quality from buyers in the past 8 years exporting time. In Aogang Optical, you can find high quanlity lenses with the most competitive prices.

Our Service: Our customer service begins tracking the processing status of products daily until you receive the product and confirm the quality.You could contact us by SKYPE,Whatsapp, e-mail, voice phone, message at any time!We guarantee the quality to all buyers all over the world, and got a high reputation about quality from buyers in the past 8 years exporting time.