What Are Progressive Lenses?

English term for progressive lens: Progressive lens is a multifocal lens, which is different from traditional reading glasses and bifocal reading glasses. Progressive lenses do not have the fatigue that the eyeball must constantly adjust the focal length when there is no dual focus. The clear dividing line between the focal lengths. It is comfortable to wear and has a beautiful appearance, which has gradually become the best choice for presbyopia people.

Progressive lens

English term for progressive lens: Progressive lens, is a multifocal lens, which is different from traditional

The concept of progressive lenses is that there are multiple focus points on the same lens.

Progressive Reading Glasses

As the human eye degenerates with age, the focal length becomes longer, and the image of objects within a distance of 50-100 cm is blurred, while objects above 3-5 meters generally have little effect. This is the so-called presbyopia, which is common to middle-aged and older people over the age of 40.

In order to correct this degradation phenomenon of the change in the focal length of the eyeball, humans have invented glasses, that is, by measuring different eyeball degradation degrees of specific individuals, designing optical lenses adapted to specific individuals fixed on the frame to re-correct the deviation of sight Focal length, this is reading glasses. The design reasons / principle of myopia glasses are the same.

Old-fashioned reading glasses generally have only one focal length, making it easier for aging people to read objects or text at close distances. If you are looking at distant objects, you must look away from the glasses, which causes a lot of trouble for use.

In order to solve this trouble, bifocal reading glasses also appeared. The designer designed the upper half of the glasses to observe objects above 3 meters, while the lower half was designed to observe the characters of objects at a close distance. So that the wearer of hyperopia glasses does not have to remove the glasses when observing different objects near / far, which provides great convenience for hyperopia people.

On the polishing of the far / near two focal lengths of the bifocal reading glasses lens, due to the different curvatures of the lens, the upper and lower parts of the lens form two distinct parts. There is a clear boundary line between the upper and lower parts of the lens, and the appearance is poor. During the wearer's use, when the eyes move from top to bottom or from bottom to top, the eyeball will constantly adjust, causing fatigue or dizziness. If the luminosity difference between distance use and near use is high, there will be a clear "image jump", which will cause dizziness and inability to judge the height of some scenes in life (such as stairs, walking).

Progressive lens

Progressive lenses are developed on the basis of bifocal lenses. The usage rate is relatively high in Europe and the United States, and the fitting time in China has only begun in nearly 10 years. Progressive lens is the transition between the two focal lengths by using the grinding technology during the transition of the two focal lengths, which is called progressive. It can be said that the progressive lens is a multifocal lens. When observing near / close objects, the wearer does not have to remove the glasses, and the line of sight between the upper and lower focal lengths is also progressive. When there is no dual focal length type, the eyeball must constantly adjust the focal length fatigue, and there is no fatigue between the two. The clear dividing line between focal lengths. The only disadvantage is that there are different levels of interference zones on both sides of the progressive film, which will make the surrounding field of view feel swimming.