What Is a Laser Goggle?
Laser goggles are protective eyewear designed to be worn when working with lasers to safeguard the eyes from potential harm.
Failure to wear laser goggles can result in serious eye damage caused by exposure to laser beams. When selecting laser safety glasses, it is essential to match the wavelength and power output of the laser in use. Additionally, the optical density (OD), which indicates how much light is transmitted, should be considered to ensure that the appropriate goggles are chosen for the specific task.
Uses of Laser Goggles
Laser goggles are worn in environments where laser processing machines or laser oscillators are employed.
Laser goggles should be worn when:
- Using processing machines equipped with laser oscillators, including welding, cutting, engraving, marking, and more.
- Performing medical laser treatments in clinics or similar settings.
- Conducting research involving laser oscillators and other laser-related activities.
Even when wearing protective goggles, it is important not to look directly into the laser beam. The lenses used in safety goggles are designed to protect against scattered laser light and not direct irradiation.
Principle of Laser Goggles
Laser goggles utilize special lenses designed to absorb scattered laser light and reduce transparency for certain wavelengths.
Laser light is characterized by its directionality, coherence, and high energy density, making it potentially harmful to the eyes even at low power levels. Different wavelengths of laser light pose varying risks to the eye, potentially affecting the cornea, retina, optic nerve, and deeper structures. Therefore, selecting appropriate safety goggles based on the laser’s wavelength, output, and OD value is crucial.
A higher OD value indicates greater laser safety, but it also reduces the transmission of visible light, potentially affecting work efficiency. It is important to choose safety goggles with an appropriate OD value that suits the nature of the work.
How to Select Laser Safety Glasses
Choosing the right laser safety glasses involves confirming the type of laser, its oscillation wavelength, and output. Select lenses and filters that match the laser’s wavelength.
Several types of laser goggles are available, including “goggles,” “spectacle,” and “front” types, some with side shields and others without. To improve workability, opt for goggles with low transmittance in the laser wavelength range and high transmittance in the rest of the visible light spectrum. Ensure a proper fit, as goggles with the wrong wavelength won’t provide adequate protection and could lead to accidents.
Even when wearing laser goggles, direct entry of laser light into the eyes cannot be completely prevented. Some laser beams, such as ultraviolet and infrared wavelengths, are invisible to the naked eye.
Other Information on Laser Goggles
Classes of Laser Goggles
Laser beams are classified based on their potential hazard level:
- Class 1: Safe for normal use, posing no hazard.
- Class 1M: Hazardous when viewed with optical instruments, within wavelengths of approximately 300~4,000nm.
- Class 2: Hazardous within wavelengths of approximately 400~700nm, but can be protected against by blinking the eyes.
- Class 2M: Similar to Class 2 but hazardous to view with optical instruments.
- Class 3R: Dangerous to view directly within wavelengths of approximately 300nm to 10mm.
- Class 3B: Generally considered safe for diffuse reflected light but dangerous for direct viewing.
- Class 4: Extremely dangerous for direct viewing and can cause damage even from diffuse reflected light, potentially leading to fires.
Some laser goggles are designed to protect multiple classes of lasers, ensuring safety when working with potentially hazardous laser beams.