Lens is a disposable product, once processed and made, can not modified, to avoid the loss can made, should be consider the correct choice.
Select lens essentials: according to their work, life needs,choose the performance of glasses should have, in the choice of glasses corrected vision, use distance, and glasses degree, but also should consider the different performance characteristics of different lenses.
1. Lens color
People who have high visual requirements for vision, color, and distance, such as students, car drivers, surgeons, and artists, should choose clear and colorless lenses. If the driver puts on the lens with heavy color, he is not sensitive to the change of distance and does not judge the distance accurately, which is easy to cause accidents.
2. The shape of the lens
The shape of the lens depends on the shape of the frame
3. Light transmittance of the lens
Optical lens with multilayer anti-reflection film, colorless optical lens and aspheric surface ultra-thin optical lens have better transmittance.
4. Thickness of lens
It is related to the size of lens diopter, the refractive index of lens, the size and shape of lens frame, the distance between pupil and light center, the axial position of astigmatism, and the properties of lens (concave and convex).
5. The weight of the lens
Related to lens materials, glass lenses are heavier than resin lenses. The same lens material is heavier than the major one and weighs less than the specific gravity, and the larger one weighs less than the volume (depending on the lens strength and shape).
6. Hardness of the lens
Glass lens than resin lens hardness is high, more wear - resistant.
7. Lens strength
Resin lens than glass lens strength, impact resistance is not easy to break.
8. Special functions of lenses
Such as anti - ultraviolet, anti - electromagnetic radiation, anti - infrared, high temperature, oil, acid and alkali resistance, anti - dispersion, anti - deformation (ultra-thin aspheric lens), anti - glare and other functions. Such as electric, gas welding lenses, computer lenses, underwater lenses, fishing lenses are different.
The above key points are very important for choosing a good lens. Do you remember them clearly?
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