Views: 200 Author: Site Editor Publish Time: 2020-12-19 Origin: Site
Progressive lenses are a kind of multi focal lens, which is widely used in Europe and America, and it appears in China 10 years ago.
Different from ordinary lenses, progressive multifocal lenses have multiple focal lengths on the same lens, which can be divided into three regions: far, middle and near.
The upper part of the lens is used to see long-distance objects, such as watching scenery, playing games and walking; the middle part of the lens is used for watching distance objects, such as watching TV, watching computer, playing cards and entertainment; the lower part of the lens is used to watch close range objects, such as reading books, reading newspapers, writing and sewing; the area marked with blue on both sides of the lens is astigmatism disorder area, which is used to correct eye habits and prevent the degree from deepening.
The so-called gradual, is the use of grinding technology to gradually transition two focal lengths. The advantage of this design is that the wearer can see far and near objects clearly without taking off the glasses when observing the far and near objects alternately. The most common examples are presbyopia, such as low power reading glasses and high magnification reading glasses. They need to be removed when you alternate between looking at distant and near objects.
Because the human eyes degenerate with age and the focal length becomes longer, the images of objects within the range of 50-100 cm are blurred, while the objects above 3-5 m are generally not affected. This is so-called presbyopia. The middle-aged and elderly people over 40 have this common phenomenon. However, most patients may prefer to choose nearsighted reading glasses or bifocal reading glasses.
The old-fashioned presbyopia glasses usually have only one focal length, which makes it easy for the aging people to read close-up objects or words. If they look at distant objects, they must move their eyes away from the glasses, which causes a lot of trouble to use. Varifocal reading glasses and focus adjustable glasses may be good choices.
Progressive lenses are different from traditional presbyopia glasses and bifocal presbyopia glasses. There is no fatigue feeling that the eyeball must constantly adjust the focal length when using the progressive lens, and there is no obvious dividing line between the two focal lengths. Progressive computer reading glasses and progressive reading glasses with transition lenses are comfortable to wear and beautiful in appearance. They have gradually become the best choice for presbyopia.
However, the multifocal glasses price is a little expensive because it is necessary to customize reading glasses according to the individual's degree.
Who are suitable for progressive lenses?
Patients over 45 years old with long distance, short distance and medium distance eye use requirements in work and life. Such as teachers, doctors, leading cadres, etc. These people are not satisfied with the traditional bifocal lenses.
The distant vision of adolescents is normal. Therefore, progressive lenses can be used to prevent myopia. Myopia in patients with myopia increases faster every year. Progressive lenses can delay and control the development of myopia.
Progressive lenses are also suitable for ametropia: single light is less than or equal to ±8.00ds, astigmatism is less than or equal to ±2.00dc, and vertical anisometropia is less than or equal to ±2.00d.
When we buy glasses, we should choose the big frame. Because the lens should be divided into far, middle and near areas, only a large frame can ensure a sufficiently wide near-use area. It is better to have a full frame, because the larger the lens, the thicker the edge of the lens. The full frame groove can cover the thickness of the lens edge.
It takes about a week to wear progressive glasses. The length of the adaptation period varies from person to person. If we feel dizzy when we wear it, we can walk slower.
Because the two sides of the lens are astigmatism disorder areas, it is not clear to see the objects on both sides through the light. We need to rotate our necks and eyeballs at the same time to see clearly.
When we go downstairs, glasses should be brought lower and we should try to see through the upper part of the lenses.
Progressive lenses are not suitable for all people. Besides the degree of myopia and presbyopia, the daily use of progressive lenses should also be considered. This is why some people say that the progressive lens is not good, and the degree of wearing it has deepened. Therefore, when we wear progressive lenses, we must choose a regular and qualified ophthalmic hospital or institution, and the optometrists will carry out the fitting.