Why do you need to wear laser safety glasses when operating lasers?

1. What is laser operation and its practical application areas

① Laser operation refers to a series of activities involving laser generation, transmission, control and application using laser equipment. The generation of laser (Light Amplification by Stimulated Emission of Radiation) is based on the principle of stimulated radiation of matter.

② The practical application areas of laser operation include laser processing, laser medical treatment, laser measurement and detection.

a. Laser processing is an important application area of laser operation. It includes laser cutting, laser welding, laser drilling, etc. In laser cutting, the laser beam is focused on the surface of the material, causing the material to melt and vaporize rapidly. By moving the laser beam or the material, a cutting seam is formed to achieve cutting of the material.

b. In the medical field, laser operation is used for a variety of treatments. For example, laser eye surgery uses laser to cut the cornea to correct vision problems such as myopia, hyperopia and astigmatism. In dermatology, lasers can be used to remove tattoos, treat pigmentation and skin vascular lesions, etc.

c. Laser can be used for distance measurement, three-dimensional morphology measurement, material composition detection, etc. In laser ranging, the distance is calculated based on the time it takes for the laser to travel back and forth to the target. For example, in construction projects, the size of a building can be quickly and accurately measured using a laser rangefinder.

Laser operation is also used in the fields of communications, scientific research, and military.

2. Why do you need to wear laser safety glasses when operating a laser?

①  Protect your eyes from laser radiation

The ultraviolet laser (100-400nm) band is mainly absorbed by the cornea. Due to its high photon energy, short-term exposure to high-intensity ultraviolet lasers may cause necrosis and shedding of corneal epithelial cells. This damage is similar to corneal abrasions, which can cause symptoms such as pain, foreign body sensation, tearing, and photophobia in the eyes, and may also trigger photochemical reactions, and even some ultraviolet lasers can penetrate the cornea to reach the lens.

Lasers in the visible light band (400-780nm) can penetrate the cornea and lens and focus on the retina. When the laser power is high enough, it will cause thermal damage to the retina.

Near-infrared laser band (780-3000nm) can penetrate the cornea and be absorbed by the lens and retina

Mid-infrared and far-infrared laser bands (3μm - 1mm) are mainly absorbed by the cornea and conjunctiva. Since their energy is mainly transmitted in the form of heat, exposure to lasers in these bands may cause burns to the cornea and conjunctiva. The degree of burns ranges from mild congestion and edema to severe corneal tissue necrosis.

② Prevent strong light from interfering with vision: strong light causes visual persistence and glare. Lasers usually have very high brightness. When the operator's eyes are directly exposed to the laser, even if the laser power is low enough to cause permanent damage, the strong light will cause visual persistence and glare.

③ Filter out harmful wavelengths of lasers, and the differences in the hazards of lasers of different wavelengths

④Laser safety glasses can block splashes and reflected light

a Prevent splash damage

In many laser processing operation scenarios, such as laser cutting and welding of metal materials, melted and vaporized metal splashes will be generated due to high temperature. These splashes have high temperatures and fast speeds. They may splash into the eyes with extremely high energy, causing corneal abrasions, burns and other injuries, and may even be embedded in the eye tissue, causing more serious consequences. Goggles can provide a solid physical barrier for the eyes, effectively preventing these splashes from directly contacting the eyes and reducing the risk of eye injuries.

b Reduce the impact of reflected light

When a laser beam is irradiated on the surface of an object, reflected light is inevitably generated. Especially on the surface of highly reflective materials, such as metals or mirrors, the energy and characteristics of the reflected light may be similar to the original laser beam. These reflected lights are also potentially dangerous and may cause accidental damage to the eyes. Goggles have special optical properties that can effectively absorb or reduce the intensity of reflected light, providing additional protection for the eyes from the harm of reflected lasers.