Square sunglasses, also called sun-shading mirrors, are used for sun-shading. People usually adjust the luminous flux by adjusting the size of their pupils under the sun. When the intensity of the light exceeds the adjustment ability of the human eyes, it will cause damage to the human eyes.
Therefore, in outdoor activities, especially in summer, it is necessary to use sunglasses to block the sun, so as to reduce the fatigue caused by eye adjustment or the damage caused by strong light stimulation. The square frame is suitable for people with rectangular faces.
