The pterigium may be large or small, wide or narrow, more or less swollen but the shape is quite characteristic. The vast majority of times we see it located on the inside of the eye (on the nose). He is always on the horizontal axis, or coming from the left or right but never up or down.
The injury that eventually leads to pterygium called pinguecula and consists of a degeneration of conjunctival tissue that is aa the izuierda or right of the cornea. It is believed to be due, at least in part, to sun exposure. Often goes unnoticed and is seen as a somewhat elevated, yellowish nodule. You can have one or two pingueculae and have no symptoms ever.
In most cases their growth is self-limited and is really small. Sometimes the pterygium may become red and cause irritation and discomfort. Only cases of significant inflammation or when grown dangerously toward the center of the cornea is treated surgically as it alters vision.
