802.11 is a Wi-Fi standard, not a frequency, both of those operate at 2.4 GHz. Bluetooth operates at frequencies between 2402 and 2480 MHz, or 2400 and 2483.5 MHz.
the answer is side shields cause the side shields gives more protection to the eyes than just the lens because the flying objects and particals can still get into your eyes even with the safty glasses but with the side shields the total risk of injury percentage goes down because the side shields helps blocks the flying objects and particals that are trying to get into your eye from the side
