TR90 Cycling Polarized Sunglasses

Function: Photochromic, polarized light and 100% UV protection
Light transmittance: 80% -18%
Color: 80% is light gray when UV is low, 18% is dark gray when UV is high
Adjustable non-slip nose pads.
Please note: 

Discoloration rate is related to UV intensity and temperature (if UV intensity and temperature are low, the discoloration speed will be slower)
Glass will only change color under UV light. Does not change color under ordinary incandescent lamps.