What are FL Pro TheraSpecs' visible light transmission (VLT)?

FL-Pro® TheraSpecs come in three different tint strengths:

• Standard strength blocks 35% of all light
• Extra strength blocks 50% of light
• Max strength blocks 74% of light

All of these tint levels were designed to filter the most problematic wavelengths and provide protection against screens, fluorescents, LEDs, and other artificial lighting.