Types of goggles:
Also known as sunglasses, the transmittance of visible light is about 20%, and it absorbs ultraviolet and infrared light better. There are many colors such as light green, light gray, light tea, etc., which are used to make sun protection and snow work protective glasses. Among them, light gray lenses have the least impact on color recognition; light tea glasses make the blue sky look darker and reduce green light transmission; light green lenses reduce red light transmission.
Gas welding goggles
The coloring agent used in this lens is mainly iron oxide, cobalt oxide, etc., which is yellow-green, can absorb light waves with a wavelength of less than 500urn, the visible light transmittance is less than 1%, and only a small amount of infrared rays can pass through. These glasses are intended for use during gas welding operations.
The short-term exposure of the ultraviolet rays generated by electric welding to the eyeball will cause damage to the cornea and conjunctival tissue (28nm light is the most serious). The strong infrared rays easily cause cloudiness of the eye lens. Welding goggles can block the above infrared and ultraviolet rays well. This lens is based on optical glass and uses coloring agents such as iron oxide, cobalt oxide, and chromium oxide, and a certain amount of cerium oxide is added to increase the absorption of ultraviolet light. Appearance is green or yellow-green. Can block all ultraviolet rays, infrared transmittance <5%, visible light transmittance is about 0.1%.
There are two types of these glasses, one is coloring iron oxide and cobalt oxide, and the filament is purple, and the other is copper oxide and manganese oxide, and the filament is white. They can all absorb dazzling glare in the band of 500-600nm (visible area sensitive to human eyes), the light transmittance at 400nm is below 12%, and they have a certain absorption effect on ultraviolet rays. They are suitable for operation in front of various industrial high-temperature furnaces Worn by personnel.
5. Crimson glass glasses: This kind of spectacle lens is a kind of dark red glass colored with cadmium sulfide and cadmium sulfenide. It can absorb all light with a wavelength below 600nm. Can be used as goggles for medical or industrial personnel when operating X-ray fluoroscopy equipment.
Laser protective glasses
There are two types of these glasses, namely reflection type and absorption type. The former uses a vacuum coating method to coat a metal film, and the reflectivity of the laser bands with wavelengths of 532nm, 694nm, and 1060nm is greater than 99.5%; the latter lens It can absorb all of the 1060nm laser band. The lens must be equipped with a closed or semi-closed frame to prevent laser light from entering the eye around the lens. Can be used as protective glasses for laser operators.
Microwave protective glasses
Microwave is an electromagnetic wave with a wavelength of about 1nm-1M. It can also cause harm to people, especially eyes.
Under the action of strong microwaves, it can cause eye fatigue, dry eyes and dizziness, and even cause cloudiness, cataracts and retinal damage. Its protection is to spray tin tetrachloride on the lens surface and metal compounds that can increase the conductivity, and to form a multilayer conductive film on the lens surface, which plays a role in shielding microwaves. Because the microwave can bypass the lens and enter the eye, the frame should also be shielded to prevent microwave damage to the eye.
Absorptive filters, because the lens absorbs some light and becomes heat release, especially infrared and some other long-wave light, because of the accumulation of heat, it makes the eyes feel uncomfortable. If a reflection filter is used, this problem can be solved well. It was introduced in the front-coated glasses that if a layer of material with a higher refractive index than the lens itself is coated on the lens surface, it will increase the reflection of light and reduce the intensity of transmitted light, which can protect it. Eyes are not harmed by strong light and harmful rays. In actual working life, in many cases, absorption and reflection are used in combination, that is, a highly reflective film is plated on colored lenses to enhance the filtering effect. For example, operators such as electric welding, chlorine arc welding, plasma cutting, etc. Wearing glasses can be solved by this method. The optical glass material produced by the glass factory is made into a glass sheet with a certain diopter and shape after a series of grinding and polishing processes in the eyeglass factory, which is called a lens (uncut lens). The preparation of glasses is to select appropriate lenses for cutting, edging and other processes to conform to the shape of the frame, and then attach the frame. Although the lenses are inspected, marked, and so on when they leave the factory, when preparing glasses, the optician should also perform procedures such as measuring, marking, and inspecting the lenses so that each pair of glasses can accurately meet the prescription requirements. , And finally achieve the purpose of correction, comfort and beauty.
The most common goggles are welder goggles with shading number 14, which can be bought in the welding equipment market. According to experts, when using the astronomical telescope or the naked eye to observe the sun, a Bard film or other filtering device must be added in advance, otherwise Burn fundus and instruments. Among them, Bard film not only has stronger contrast, but also makes the sun show true colors. The reporter searched on Taobao.com and found that in most online shops selling paper eclipse observation mirrors, they were marked with "Bad film", but most of them did not indicate whether they had been tested by professional departments. In this regard, relevant experts reminded that according to international standards, an observation mirror using a 5.0 Bard film density can be used for total solar eclipse observation. Qualified protective glasses face the sun, and the sun will appear gray and white, and the ground seen will be black. , Basically can not see other things.