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公告 |
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Three mistakes in glasses(2)
lpw7878 发表于 2012/9/6 15:39:00 |
Misunderstanding bus: thin lenses of good material of your good
Ray ban sunglasses lenses are as thin as possible is good, your material is, the better it? The answer is no.
In General, more thin lenses, light transmission rate, the better. But
not equal to high light transmission rate, the better. And, if it is
below 300 degrees of myopia, the lens itself is not thick; one Deputy
ultra-thin lenses don't have to spend a lot of money.
The
materials in the past have been respected throughout the world of
expensive Crystal lenses, but in fact Crystal lenses would not be
appropriate to do.
Crystal hardness, easy to wear, but there
are impurities in natural quartz, stripe and bubble-prone, will double
refraction of light through, stacks of shadow. People advocating the
Crystal lens, is the low rate of absorption of ultraviolet and infrared,
the lens temperature is relatively low, have a sense of cool.
Analysis: ray ban sunglasses sale lenses from the materials into three categories: glass, resin film, space mirrors, each with its characteristic.
Optical properties of glass, is not easy to scratch, high refractive
index. But fragile glass tablets, material preference, select pieces of
glass and fewer people.
Resin piece is light, not easily
broken, ultraviolet resistant functions well. Most people prefer to use.
Advantages and disadvantages of plastic lenses depend on a variety of
factors (new lenses will be added):
1, the index of refraction: the higher the refractive index, then more thin lenses, the price is relatively high.
2, hardness: hardness low resin piece, easy smudging, but after adding a
hard anti-flower treatment, can increase the hardness of resin film.
3, plus film: enhanced films reduce lens reflection, increasing the light transmission rate of lenses to improve clarity.
4, non-spherical designs: the lens of relatively flat lenses, clear, comfortable Visual effects can be achieved.
Space lenses, also known as the PC Tablet, but lighter than resin piece
more impact-resistant, thin, below 380 NM UV-proof. General crowd
recommended giving interested in sports or outdoor activities.
Reminder: high myopia should use high refractive index spherical lens
elements, thin lenses, and aesthetically pleasing. Low myopia, there is
no need to select a high refractive index, and made of 1.5 or 1.56
refractive index. Moderate myopia, you can consider the low refractive
index spherical cheap ray bans lenses, can achieve the same effect of high refractive index. |
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