Technical indicators Sunglasses

Vertex deviation

Cheap Ray Ban Sunglasses nominal vertex value should be 0.00D, lens manufacturing deviations or lens and frame assembly does not match, are likely to produce the deviation of the vertex (the vertex with positive or negative), if beyond a certain range, the wearer may feel as deformation, seriously will affect the wearer's vision health. Corresponding to the GB10810.1 "glasses first parts: single light and multiform lenses" national standard requirements in Table 1, the ball lens foci-meter tolerance of ± 0.12D; column lens foci-meter tolerance of ± 0.09D.

Prism degree

Prism degree sunglasses should be 0 Δ, if the lens with prism degree, will produce visual shift of focus, if exceed allowable limits, it may lead to binocular vision can not one, not a sense of balance and level, increase the wearer's ophthalmologist and optic nerve disorderly adjustment, serious will cause nerve disorder or Arabic’s. According to the GB10810.1 requirements in Table 4, the prism degree of tolerance is 0.25.

Light transmittance (t V)

For light Cheap Ray Bans sunglasses, the light transmission ratio should be >40%; for the sun mirror, the light transmittance in the range of 8% ~ 40%. Optical transmission project is an important index of the sunglasses feature. China's current standard according to this feature will be divided into 3 categories: sunglasses, light-colored sunglasses and special use sunglasses, European and inteational standards are divided into 5 categories.

If the use of light-colored Sunglasses used for shade, good effect of the wearer would be unable to obtain a sunshade, such as long time in the sun more outdoor activities, the wearer will still feel tired because of the strong stimulus. Light Ray Ban Sunglasses play the role of decoration, or is not strong in the sun's interior. On the contrary, in the indoor or do not need to wear sunglasses to block the strong sunlight place, will be due to excessive enlarge pupil and discomfort, fatigue. In the shade of a transmission is relatively small, the product is not suitable for cyclists and motorists wearing, because cyclists and motorists traveling speed is faster than the pedestrian, transmission will affect their ability to react ratio is too low.