I try to take care of my skin by avoiding excessive sun exposure
That's a smart choice. I don't like spending much time in the sun myself.
It gets dangerous with UV exposure being the primary cause of melanoma
Melanoma is one of the main reasons I don't enjoy prolonged sun exposure and have never used a tanning bed. I'd rather be pale and cancer free.
Sunburn
Sunburn is a form of radiation burn that affects living tissue, such as skin, that results from an overexposure to ultraviolet (UV) radiation, commonly from the Sun. Common symptoms in humans and other animals include red or reddish skin that is hot to the touch, pain, general fatigue, and mild dizziness. An excess of UV radiation can be life-threatening in extreme cases. Excessive UV radiation is the leading cause of primarily non-malignant skin tumors. 
Sunburn is an inflammatory response in the
often have high rates of cataracts because of the increased levels of UV radiation in the upper atmosphere. It is hypothesized that depletion of the ozone layer and a consequent increase in levels of UV light on the ground may increase future rates of cataracts. Note that the lens filters UV light, so if it is removed via surgery, one may be able to see UV light.
Prolonged exposure to ultraviolet radiation from the sun can lead to melanoma and other skin malignancies. Clear evidence establishes ultraviolet radiation, especially the non-