First, what are the types of lenses?
1. Lenses can be divided into different materials according to different materials:
(1) Resin lens
(2) Glass lens
(3) PC lens.
2. Resin lenses can be divided into: according to the refractive index:
(1) 1.50 refractive index
(2) 1.56 refractive index
(3) 1.60 refractive index
(4) 1.67 refractive index
(5) 1.74 refractive index.
More commonly used in glass lenses are lenses with a refractive index of 1.8 and a refractive index of 1.9.
3. Lenses can be divided into different functions according to their functions:
(1) Single lens
(2) defocused lens
(3) Progressive multifocal lens
(4) Anti-fatigue lens
(5) color changing lens
(6) polarized lenses
(7) anti-blue lens
(8) Driving lenses, etc.
Second, which resin lens, glass lens, PC lens?
The resin lens is light in material, strong in impact resistance, not easily broken, and has high light transmittance, and has become a mainstream lens. Glass lenses are rarely selected because of their heavy weight and their fragility.
However, glass lenses have the advantage of high refractive index, and for high myopia customers, they can make thinner and more beautiful lenses. PC lenses are extremely tough and not easily broken. They are especially suitable for sports eyewears.com/ target='_blank'>glasses.
3. What lens do I need to choose?
1. For adolescents in the school age, it is recommended to choose anti-fatigue lenses or defocused lenses.
Generally, the anti-fatigue lens is based on the principle of a progressive lens, and a positive degree of 0.50D~1.00D is added to the near-eyewears.com/optical-frame.html target='_blank'>optical area of the lens, so that the adjustment function of the eye is relaxed when the eye is near, and the fatigue of the eye is effectively alleviated.
The function of the defocused lens is to form a myopic defocusing effect in the peripheral retina, which can effectively delay the adaptive growth of the eye axis and the development of myopia.
2. Most of the young and middle-aged people are office workers. They are facing computer work for a long time. It is recommended to choose anti-blue glasses.
Anti-Blu-ray glasses can effectively reduce the harmful damage of harmful blue light to the eyes. Through the contrast detection of portable spectrum analyzer, after using anti-Blu-ray glasses, the intensity of blue light emitted by the screen of the mobile phone is effectively suppressed, reducing the harmful blue light to the eyes.
The anti-blue light glasses mainly reflect the harmful blue light through the surface coating of the lens, or add the anti-blue light factor through the lens substrate to absorb the harmful blue light, thereby achieving the barrier against harmful blue light and protecting the eyes.
3. For the middle-aged and elderly people, it is recommended to choose progressive multifocal glasses.
Because with the increase of age, the eye regulation function is reduced, and the phenomenon of presbyopia will occur. For elderly friends who have worn a telescope, after the appearance of presbyopia, two or more pairs of glasses are usually needed to meet the needs of far-sightedness, fancy, and near-looking. Progressive multifocal glasses can fully solve this series of problems and achieve the effect of "one mirror and more energy".