This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Conjunctiva, Subject name: Ophthalmology
Visual impairments in pterygium is due to - 
Select and explain. 
A. Astigmatism, B. Myopia, C. Hypermetropia, D. Hazy cornea
A: Astigmatism
Answer: A: Astigmatism 
Explanation: Visual disturbances occur when pterygium encroches the pupillary area or due to corneal astigmatism induced due to fibrosis in the regressive stage. Reference : Khurana 7th edition, page : 89