They’re called shades for a reason. Pick the perfect sunglasses, a pair that blocks 99 to 100% of UVA and UVB rays, absorbs UV up to 400 nanometres, or meets American National Standards Institute UV requirements, says 
Dr Lee Duffner, an ophthalmologist. Then test lens quality: close one eye and move the shades from your forehead to your face. Repeat with the other eye closed. Do objects shift? “The movement should be minimal and in the same vertical direction in each lens,” says Fraser Horn, an associate dean of optometry. Here’s what you need 
to commute, compete or kick back.