How To Chose Certified Laser Safety Glasses

Laser technology has revolutionized various industries, from healthcare and manufacturing to research and entertainment. Those who need to use the technology, both at work and for private purposes, must definitely remember stringent precautions to prevent potential eye damage caused by laser beams. Laser protection glasses are specifically designed to shield the eyes from harmful laser radiation. What are the different laser classes and the appropriate filters required in laser protection glasses for each class?

Understanding laser classes

Lasers are classified based on their potential to cause harm to the eyes and skin. The International Electrotechnical Commission (IEC) developed the classification system that categorises lasers into four main classes.

Classes 1–4 suggest how harmful the laser beams are, starting with 1 as the safest one and 4 as the most hazardous. According to the class the user experiences, specific laser protection needs to be used in a form of laser safety glasses to block the harmful beams and ensure 100% protection.

#1 Class 1 (1M)

Class 1 (and 1M) lasers are generally considered safe under normal operating conditions because they do not emit hazardous levels of laser radiation. Some everyday devices emit that many beams, for example, laser pointers or DVD players. As the risk is extremely low in the case of class 1 lasers, no protection glasses are required. The absence of the necessity of wearing protective glasses doesn’t mean you can use the devices irresponsibly.

#2 Class 2 (2M)

Devices emitting class 2 (and 2M) laser beams are still not likely to cause eye injury due to the human blink reflex. Class 2 means the laser beams are visible, yet, the laser protection glasses are typically not necessary. Similarly to class 1, laser beams are not to be experienced by direct contact with the eyes or skin.

#3 Class 3R

Class 3R, or Class 3A, is the first laser class that may potentially cause eye injuries when viewed directly. The power of laser beams is low to moderate, and it can be used in laser pointers, laser levels, and some industrial applications.

The risk of eye damage that class 3R poses means the necessity of using laser protection glasses with filters of adequate attenuation in the visible range. To assess the laser protection level required, the wavelength is analysed, and in this case, the filter we need is an absorptive filer. The required OD for Class 3R laser protective glasses typically ranges from 1.5 to 2.5, depending on the laser’s wavelength.

#4 Class 3B

Laser of Class 3B are quite dangerous as they emit higher power levels causing immediate eye injuries when viewed directly. Such laser beams are used in research, industrial applications, and medical procedures. It’s necessary to wear laser-protective glasses, to prevent eye damage.

The filters of glasses for class 3B offer high attenuation across a broader spectrum. They’re often made of absorptive or reflective materials, depending on the laser’s wavelength and power. For Class 3B lasers, the required OD typically ranges from 3.0 to 5.0.

The most hazardous lasers, able to cause severe eye injuries, and also skin burns, or fire hazards, are class 4 lasers. They are used in research, industrial cutting, welding, or medical procedures. As the use of such laser is almost professional, the laser protective glasses need to be trustworthy, it’s even recommended to wear goggles. The recommended laser protective glasses must have high optical density, which depends on the laser’s wavelength and power.