Hot summer, the sun in the sky, more outdoor activities or long time driving friends often feel dry eyes, pain, photophobia, tearing, unwilling to open their eyes, especially in the afternoon feeling more pronounced, this is more ultraviolet rays in the summer sun, due to ultraviolet light caused by eye damage. Ultraviolet light on the eye tissue has photochemical effects, so that the protein coagulation denaturation, in severe cases will cause corneal epithelial necrosis and detachment, can be in the irradiation of 3-12 hours after the onset of the stinging pain, photophobia, tearing and foreign body sensation. So think about wearing sunglasses or color-changing glasses to protect your eyes under the hot summer sun.