First, we need to understand what a laser is. The principle of the laser was discovered by the famous American physicist Albert Einstein in 1916, but it was not until 1960 that the first laser was successfully manufactured. In the 20th century, laser after atomic energy, the computer, semiconductor, human’s other major invention, known as “the fastest knife”, “the most accurate ruler”, “the brightest light” and “strange laser”. The laser comes into being under the background of theoretical preparation and urgent need of production practice. As soon as it comes out, it has obtained extraordinary rapid development.
The development of laser makes ancient optical science and optical technology get a new life and leads to a whole new industry. The laser can make people effectively use unprecedented advanced methods and means to obtain remarkable benefits and results, thus promoting the development of productive forces. The downstream demand of China’s laser industry is mainly laser processing, optical communication, laser measurement, laser, laser components, laser medical treatment; their market share is 43.5%, 25.7%, 14.3%, 6.1%, 4.8%, 3.7%, respectively.
Use laser safety glasses to protect your eyes
a. Laser damage to eyes
Laser wavelength and eye injury. In laser injury, eye injury is the most serious. Although laser technology has been integrated into our daily life, the harm of lasers can not be ignored. The laser wavelength in visible and near-infrared light, the eye refractive medium absorption rate is low, transmission is high, and the refractive medium focusing ability (light concentration) is vital. When high intensity visible or near-infrared light enters the eye, it can pass through the refractive medium of the human eye and accumulate light on the retina. At this time, the laser energy density and power density on the retina increase to thousands or even tens of thousands of times, a large number of light energy in an instant in the retina, resulting in a rapid rise in the temperature of the retina’s photoreceptor cell layer, so that the photoreceptor cells coagulation degeneration necrosis and lose the role of photoreceptors. When the laser is concentrated on photoreceptor cells, the protein coagulation caused by overheating is irreversible damage. Once damaged, permanent blindness can result.
Different wavelengths of the laser will have other effects on the eye. Far infrared laser damage to the eye is mainly cornea; this is because this kind of wavelength of the laser is almost all absorbed by the cornea, so the cornea damage is the most serious, mainly cause keratitis and conjunctivitis, patients feel eye pain, foreign body like stimulation, fear of light, tears, eye congestion, vision decline. Far-infrared light damage should be covered to protect the eye, prevent infection, symptomatic treatment.
Uv laser damage to the eye is mainly the cornea and lens; this band of UV laser is almost all absorbed by the lens of the eye and far to the cornea absorption, which can cause lens and cornea opacity.
Lasers usually carry a laser warning label with a safety level number:
Class I/1: Usually, the beam is completely enclosed, such as in a CD or DVD player.
Class II/2: Safe under normal operating conditions. This type of equipment is usually less than 1mW in power, such as a laser designator.
Class IIIa/3R: Power usually reaches 5mW; gazing at this beam for a few seconds causes immediate retinal damage.
Class IIIb/3B: Causes immediate eye damage when exposed.
Class IV/4: Lasers can burn the skin, and even scattered laser light can cause eye and skin damage. This is when laser safety eyes are needed to protect your eyes.
b. The working principle of laser safety glasses
Laser protective goggles are a special kind of glasses that can prevent or reduce the harm of lasers to human eyes. Laser safety goggles are highly efficient and safe goggles, suitable for various lasers and Laser Pointers. This series of optical safety glasses wear comfortable, beautiful, safe, and reliable. Its optical safety performance fully meets THE EN207; laser safety glasses with absorption types, which can Omni-directional protection of specific bands of laser and strong light. Suitable for a variety of laser equipment.The visible light transmittance have 30%,50%,80% etc.. Optical density have OD5+, OD6+, OD7+ etc..
How to choose laser safety glasses
So how should we choose laser safety glasses? The primary safety levels of laser goggles in the world are ANSI Z136 and CE EN207.
Safety levels and bars and the most crucial guidance criteria for the selection of laser goggles, in addition to the UV safety certification, can also consider the following points:
1, laser parameters: output wavelength (whether multiple wavelengths), pulse width, power density.
2, the Optical Density of laser goggles (OD): the more significant the OD value, the stronger the protection ability of laser protective glasses.,
3, visible light transmittance, the higher the transmittance, the better the visual view. The transmittance of some laser protective glasses will be less than 20%, or even to about 10%. At this time, additional auxiliary lighting should be considered.
4, the style of laser goggles: laser goggles can worn on the outside of the myopia glasses; the size of the laser goggles is appropriate, whether the laser goggles can effectively block the reflection and refraction light from all directions.
a. What is wavelength?
What is wavelength? Lasers have the same wavelength as ordinary light, ranging from infrared to ultraviolet light. Wavelengths are on the order of a few thousand nanometers or less. The closer you go to ultraviolet light, the shorter the wavelength of a laser, which can be hundreds of nanometers or more minor.
b. What is OD (Optical Density)?
What is optical density? A complex property of a material that slows down the propagation of light and produces a refraction effect.
c. What is transmittance?
What is transmittance? In the incident light flux leaving from the incident surface or the incident surface of the medium to the other side, the ratio of the radiant energy projected and passing through the object to the total radiant energy projected on the object is called the transmittance of the thing.
d. Choose laser safety glasses according to the actual working environment
According to the actual working environment to choose laser safety glasses. Laser goggles: attenuation or absorption of laser energy, mainly used in laser processing, optical laboratories, and other workplaces.
Through the above introduction, I believe that you understand laser safety glasses and can choose their laser safety glasses according to their actual situation. Finally, warm tips, eyes are our most vulnerable parts, pay attention not to use eyes too much.