sunglasses 2123

8 common questions when choosing sunglasses

What are the meanings of the 1, 2, 3, and 4 on the sunglasses tag? First, we need to understand the word: transmittance. Transmittance, also known as the transmission coefficient, refers to the ratio of the luminous flux through the lens to the incident luminous flux. Directly speaking, it is the transmittance or transmittance of …

8 common questions when choosing sunglasses Read More »