Pterygium. Pterygium:very common, abnormal growth of clear covering (conjunctiva) of white part of the eye (sclera) over the cornea (window of the eye). If severe and causing discomfort or red, it can be removed with surgery. It is generally benign. It is due to excess sun/UV exposure usually. Prevention is only remedy. Avoid sun (sunglasses, hat); avoid smoking. Natural rx info: see eyedoc2020.blogspot.com.
Nothing or surgery. You don't have to do anything if you choose not to. If it bothers you, you can use artificial tears to lubricate it. If it is a cosmetic concern, an ophthalmologist can cosmetically remove it for you.