UV rays are invisible, so they are often ignored. But UV rays actually cause a lot of damage to the eyes, and this damage is cumulative and difficult to recover from. UV rays enter from the outside of the eye to the inside, producing damage of varying sizes from the conjunctiva, cornea, lens, vitreous humor to the retina. The following are the types of damage that can be done to the eye: 1. Pterygium It is generally believed that its occurrence is closely related to long-term UV radiation UVA and UVB, with a higher incidence in men than in women, and is commonly seen in communities such as farmers and fishermen who are exposed to UV light for long periods of time. 2. electrophthalmic uveitis UVA can cause acute corneal epidermal pitting, which is common among welders, and also among mountain climbers as mentioned above. 3. cataracts i.e. clouding of the lens, some studies have shown that an extra hour of sunlight per day increases the likelihood of cataracts by 10%. Why is the degree of cataract seen in highland areas such as Tibet often heavier, this is because the highland areas are more intense ultraviolet light. 4. macular degeneration Macular degeneration is one of the main causes of vision loss in middle and old age, and excessive UV light can damage the macula. 5. Eyelid skin cancer Prolonged overexposure to the sun is likely to cause eyelid skin cancer around the eyes. UV rays are not exclusive to summer, they are with us all year round, so preventing UV damage to the eyes is an important task we must do all year round.