Knowledge of Glasses
What does the kind of glasses have ，what glasses frame to material good?
The common types of glasses are as follows:
1.Sunglasses
Sunglasses also known as sunglasses, is to protect the eyes designed glasses, lens is often black or dark, to avoid sunlight to stimulate the eye.Also can serve as the hairdressing of fashionable fashionable person or reflect the special adorn article of individual style. Normal prevent ultraviolet ray sunglasses outer packing according to national standard must mark prevent ultraviolet ray grade (UV), mark has UVA, UVB, UV400 3 kinds.For short trips out for fun, opt for regular sunglasses, while for long drives and long trips it's best to opt for more powerful polarized sunglasses.
2. Myopia glasses
Myopia glasses, basically be to use the concave lens with proper focal degree, make the light ray is diverged appropriately through concave lens, form clear image on retina after refracting through the eye again.Myopic glasses have a certain preventive effect on the complications caused by high myopia.
3.Reading glasses
Reading glasses is a convex lens designed to correct age-related presbyopia in the eye lens.Reading glasses lens has the optical index that a lot of national standard sets like myopia lens, also have a few special use rules.In order to correct the senile degenerative presbyopia of the eye lens, in order to reduce the retinal damage caused by ULTRAVIOLET and infrared rays, the optical blue lens can be selected for wearing distant glasses.It is important to note that wearing reading glasses also requires optometry.
4.Contact lenses
Contact lenses, which can both correct vision and remove the inconvenience caused by glasses, have become a fashion trend, but contact lens hygiene is crucial.The arc of a contact lens should match that of your eyeball. Asians typically have a base arc of 8.4 or 8.6.The thinner the center thickness is generally the more comfortable, 0.04 mm is relatively thin;The lower the water content, the less likely the eye will dry out, because the lens has a high water content, you need to rely on tears to keep the lens water content.
The frames are divided into the following :
1) Carbon fiber mirror frame
Carbon fiber frames are light, slightly large, elastic, high temperature resistant, corrosion resistant, radiation resistant, etc. In addition, they are stronger than steel, less dense than aluminum, more corrosion resistant than stainless steel, and more high temperature resistant than heat resistant steel, which is a relatively new glasses material.
2) Acetate Frame
Acetate frame is a fashionable and classic spectacle frame with fine quality, durability, diverse colors, strong texture, easy to process and no deformation at room temperature.
3) TR90 Frame
Tr90 frames float in high concentrations of salt water and are resistant to wear, impact and high temperatures.Due to its good flexibility, good elasticity and impact resistance, non-toxicity, anti-allergy, it is the most widely used lens frame material at present.
4) PC Frame
PC frame high strength, strong hardness, no deformation, rich color, translucent, often used for sunglasses or fashion, decorative glasses.But its toughness is small, more difficult to adapt to the curve of the head, also easy to break, must add something tough.
In a word, according to their needs to choose, choose their favorite style and what material, you can decide, I hope the above content is helpful.
