This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
Which of the following condition is associated with Stockers' line? 
Select and explain. 
A. Pterygium, B. Pinguecula, C. Epidermal melanosis, D. Congenital ocular melanosis
A: Pterygium
Answer: A: Pterygium 
Explanation: A pterygium is a fleshy, triangular encroachment of a pinguecula onto the cornea, usually on the nasal side bilaterally. The cause of pterygium is believed to be related to ultraviolet and dust exposure. Clinically, a characteristic iron line (Stocker's line) may be seen at the advancing front of a pterygium. If the pterygium is enlarging and encroaches on the pupillary area, it should be removed surgically. Ref: Ophthalmology by Myron Yanoff, Jay S. Duker, James J. Augsburger, 2009, Page 364.