Manufacturer for Photogray Sunglasses - 1.56 Bifocal Flat top / Round Top / Blended HMC optical lenses – Boris

Production Details

There are only two degrees on the bifocal lenses, which are divided into upper light and lower light. Both upper light and lower light can be myopia, hyperopia, astigmatism, etc., but the upper light is deeper than the upper light for myopia and shallower for farsightedness.

Progressive is developed on the basis of double light. It not only has the characteristics of double light, including top light and bottom light, but also has a gradual process in the middle. The degree between top light and bottom light is a gradual change process.

On the surface, it is obvious to see the difference between the double light. The dividing line or the junction between the upper light and the lower light can be seen, but the surface of the progressive lens cannot see any difference.

With the transition zone, there is no elephant jump problem. That is, gradually from far to near, from near to far, if there is no transition zone, from near to far, from far to near, there is no buffer overshoot.

Production Introduction

Bifocal refers to two different dioptric powers on the same lens, two dioptric powers are distributed in different areas of the lens, the area used to see far is called the distance zone, which is located in the upper half of the lens; the area used to see near is called the near zone, which is located in the lower half of the lens.

Advantages of bifocals: You can see objects at a distance through the far vision area of a pair of lenses, and you can see objects at a close distance through the near vision area of the same pair of lenses. You don’t need to carry two pairs of glasses with you, and you don’t need to switch between distance and near glasses frequently.

Disadvantages of bifocals: The field of view is smaller than that of single-vision lenses, especially near vision. For example, reading books and newspapers needs to cooperate with head movements. There are optical defects of jumping and image displacement, and there is a dividing line, which is easy to be seen wearing. Expose age with bifocals.

Product Process

Product Video