The sun contains a form of invisible light which is called ultraviolet (UV) light. UV light is much higher energy than the light we can see, and causes the skin to tan but also age, burn, and develop skin cancer. The melanin in your skin, which is more prevalent in darker skinned individuals, protects your skin from the sun. In order to avoid the harmful effects of UV light, it is a really good idea to wear sunscreen when out in the sun. The lighter your natural skin color, the more important it is to add protection in the form of sunscreen.
But what about your eyes? You can’t put sunscreen on your eyes. And only a small part of the eye has melanin for protection (the more brown the eyes, the more melanin, but as mentioned that is only for a small portion of the eye). Most of the eye has little protection from the high-energy, damaging UV light rays.These rays are partially filtered by the cornea at the front of the eye, but large amounts enter the eye, where they are the primary cause of cataracts and macular degeneration, the main cause of blindness in the United States.
So it is a very, very good idea to protect your eyes from the harmful rays of the sun. I cringe when I am out at the beach, or on a hiking trail or the bike path, and I see people without sunglasses. And there are a lot of people who do not wear sunglasses. Even on a cloudy day, there is plenty of UV light to cause harm. Sunglasses are the sunscreen for your eyes. Please wear them all the time when in the sun.