What are Z-Blue TheraSpecs' visible light transmission (VLT)?

TheraSpecs Z-Blue™ come in three different tint strengths: "standard" - which blocks 35% of light, "extra" - which blocks 50% of light, and "max" which blocks 84% of light.

Z-Blue is designed for wearing around flashing or strobing lights, as well as repeating patterns or for general light sensitivity. We recommend Z-Blue (in Extra or Max strength) for people looking for protection for severe photosensitivity; we recommend Z-Blue (in Standard or Extra strength) for general visual hypersensitivity to the environment.