Sunglasses in addition to can reduce the radiation intensity of visible light, can also reduce the ultraviolet and infrared radiation.
On the basic requirement of sunglasses are: eliminate unwanted radiation may have damage to the eyes;
Reduce the environment light intensity into eyes, provide clear, comfortable functional vision;
Can maintain normal color vision, reflected in the rapid and accurate identification of traffic lights;
Maintaining quantity dark adaptation or night vision;
Shock resistance and good wear resistance performance, etc.
This article is to introduce the sunglasses reduce light radiation is by what way.
Sunglasses to reduce the absorption of optical radiation primarily through the lens of materials and surface reflection: 1.
Absorption of glass, is stain evenly distributed in the production process to the lens material.
Usually by adding metal oxides in the lens the realization of the aim of radiation protection.
Adding iron oxide in the glass can absorb 95% of UV and IR radiation.
Add metal oxide generally makes the lens produce change color, such as blue cobalt oxide, chrome oxide green, cyan copper oxide.
Add silicate in glass and boric acid can increase the UV transmittance.
Absorption resin lens is in manufacturing process of lenses or surface processing and cutting edge will be after the completion of organic pigments are added to the lens.
Color absorption filter can be used to improve the visual function.
Filter, in fact, change is the contrast between object and background.
But only by the color of the lens or dye to determine its radiation protection function is inappropriate, such as gray or neutral glass can usually through ultraviolet and infrared ray, is not suitable for used as a professional UV and IR protective goggles, but because it doesn't affect the color, it can be used as ordinary sunglasses.
Absorption of resin, refers to the resin material or immerse into the mirror to dye, dye can penetrate the surface of 1 mm.
CR39 can absorb ultraviolet and visible light and infrared absorption of lens distortion.
PC material can absorb infrared light.
But the color of the resin filter does not make the light characteristics.
Reflection filter, after vacuum in the lens surface coated with a thin layer of metal film, can increase the table surface reflection.
Reflective lenses by excessive radiation reflection and radiation protection.
As a result of the film surface and air directly after contact, can lead to high rates of reflection, usually in the above and then coated with a layer of magnesium fluoride (
The minus reflection film)
To reduce the surface reflection after too much into the eyes.
Surface coated reflective film reflection type filter.
Reflective lenses are mainly in the lens surface with a layer of vacuum plating metal film, can through the reflection of infrared and visible light, but to the uv absorption ability is not very strong.
Gradient dyeing, the dyeing depth continuous change appears in the lens surface, usually used for resin lenses.
The polarization filter.
This lens in addition to absorb excessive radiation, can also absorb the reflective surface of plane polarized light.
Reflection is completely plane polarized light, the vibration plane and parallel to the reflective surface (
, if the polarization filter lens set the partial vibration of the shaft as the vertical direction, the reflected light will be absorbed.
Thus, the polarization filter can filter the reflected glare of light, make the eyes see is unpolarized light irradiation of the object.
The polaroid transfer polarized light is about 32% of the incident light.
Is composed of multilayer electrical insulating film, make specific wavelength of the spectrum.
By controlling the membrane layer of material (
The control index of refraction)
What can be changed through the light wavelength.
Interference in the mirror is more sensitive to incident Angle and temperature change, change the incident Angle and temperature will change wave interference, which changes the wavelength of light through.
Besides polarizer, sunglasses are generally not eliminate glare, also do not change the contrast.
Sunglasses only can reduce the glare from the eye tolerance levels of intensity.
Ordinary sunglasses in the same proportion to absorb radiation from the object and its background intensity, so the contrast ratio doesn't change.
Special-purpose sunglasses can be in different proportion to absorb the light of the object and background, so as to change the contrast.
Glass lens light transmittance to under 4096 to as protection with sunglasses.
Color sunglasses can change the eye's ability to distinguish colors, so can't drive at night usually wearing sunglasses.
Two pieces of glass lens light transmittance of differences affect the depth perception.
The sun lens surface machining quality is bad cause visual distortion, headache, eye fatigue and other symptoms.