Visible Light Transmission, commonly called VLT, describes how much visible light passes through laser safety lenses.

Higher VLT values create brighter viewing conditions, while lower values produce darker lenses.

Laser safety glasses must balance visible light transmission with wavelength attenuation. Filters designed for certain wavelengths may naturally reduce visible brightness depending on the optical design.

In many applications, users need protective eyewear that provides both effective attenuation and practical workplace visibility.

Manufacturers typically list VLT percentages alongside wavelength and optical density specifications.

Understanding VLT can help users select laser eyewear appropriate for their working environment.