What glasses should be worn for laser glare?

What is the cause of laser glare?

1. Because laser is directional and energy-concentrated, laser is different from ordinary light. The light emitted by the light source of ordinary light is scattered in all directions, while laser passes through some devices to allow the light in the beam to propagate highly synchronously in the same direction, and the energy will be highly concentrated on a beam with a diameter of only a few millimeters. When this highly concentrated energy beam enters our human eyes, it will produce huge energy deposition in a small area in our eyes (such as the retina). Take our common laser pen as an example. Although the power of the laser pen is very low (about 5 milliwatts), the energy of the laser it emits at the focal point is much higher than that of the same ordinary light. If the light of the laser pen accidentally hits the eyes directly, it will also feel dazzling.

2. The human eye has absorption of lasers. The retina will absorb a large amount of visible light and near-infrared lasers (400-1400nm) that pass through the cornea and lens, causing burns, glare, and decreased vision. The cornea and lens absorb ultraviolet lasers. If the intensity of ultraviolet lasers exceeds the tolerance limit of the cornea, it will cause damage to corneal epithelial cells, resulting in pain, tearing, photophobia and other glaring symptoms. Long-term or high-intensity laser irradiation may cause lens opacity, that is, cataracts, accompanied by glare and blurred vision.

Because lasers are glaring, and different lasers damage different parts of the eyes, what kind of laser safety glasses we wear should be selected according to the following principles:

1. Choose according to different types of lasers:

Ultraviolet laser protection: Ultraviolet laser wavelength range: 100-400nm, you need to choose protective glasses that can effectively block ultraviolet rays, such as our LP-VHP laser protective glasses, which are used for eye protection in scenes such as ultraviolet laser lithography, laser medical beauty (such as ultraviolet laser freckle removal, etc.).

Visible laser protection: The wavelength range of visible light is approximately: 400-780nm, such as common red laser (650nm, 694nm), green (532nm), and blue (450nm) lasers. The lenses of protective glasses for visible light lasers have different colors. For example, our LP-RHP red laser protective glasses have blue lenses, and our LP-GHP green laser protective glasses have orange lenses.

Near-infrared laser protection: The band range is generally 780 - 1100nm, such as our LP-DTY and LP-YHP-2 laser protective glasses, which use absorbent materials that absorb specific wavelengths and are commonly used for industrial laser cutting, welding, and eye protection in military infrared laser equipment use scenarios.

2. Choose laser safety glasses according to laser intensity

The protective ability of laser protective glasses is usually measured by optical density (OD). Optical density refers to the degree of attenuation of the lens to the laser. For example, protective glasses with an optical density of 3 can attenuate the laser intensity to one thousandth of the original. If you are in a high-power laser environment, such as industrial high-power laser cutting equipment (several kilowatts or even tens of thousands of watts), you need to choose protective glasses with a higher optical density. Laser protective glasses with an optical density of 7 or above are recommended. For low-power laser equipment, such as some teaching laser pens, protective glasses with an optical density of 2-3 may be sufficient.

3. Choose according to transmittance and application scenarios

Transmittance refers to the ratio of the luminous flux passing through the goggles to the incident luminous flux. A higher transmittance allows you to observe the work scene more clearly when wearing goggles, but this also requires sufficient protection. For example, for some laser marking work that requires precise operation, goggles with better transmittance allow operators to better see the marking position. For the field of laser medical treatment and laser medical beauty, laser protective glasses are required to have a high transmittance to ensure that the operation and the position where the laser operation needs to be performed can be clearly seen. For example, our LP-ATD, LP-YHP-2 and other laser protective glasses are very popular in the laser medical and optical medical beauty industries. The transmittance of laser goggles mainly depends on the application scenario of the laser equipment. When performing laser handheld welding, goggles with lower transmittance are required, because the sparks generated during welding may be accompanied by dazzling white flashes. Using goggles with lower transmittance will avoid the damage and irritation of sparks and dazzling white flashes to the glasses.

4. The most important thing is that the selected laser safety glasses must comply with relevant safety standards. It is necessary to ensure that the laser goggles comply with relevant international or domestic safety standards, such as the Z136 standard of the American National Standards Institute (ANSI) and the CE standard of the European Union. These standards specify the minimum requirements for laser goggles in terms of protective performance, optical quality, etc. Goggles that meet the standards are more guaranteed in terms of quality and safety.