What Do Laser Safety Glasses Markings Mean? (ANSI Z136 Explained)

Laser safety glasses in the United States are permanently marked with information required for compliance with ANSI Z136 standards. These markings confirm whether the eyewear is appropriate for a specific laser hazard.

Wavelength Identification

Markings show the wavelength range (nm) the lenses protect against. Protection is only valid within that range.

Optical Density (OD) Values

OD values indicate how much laser radiation is attenuated.

Example:

• OD 4 → 10,000× reduction

• OD 6 → 1,000,000× reduction

ANSI Z136 provides guidance for determining minimum OD based on exposure risk.

ANSI & EN Codes

Many U.S. laser glasses reference:

• ANSI Z136

• FDA / CDRH

• EN 207 / EN 208 (international)