This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Glaucoma, Subject name: Ophthalmology
Sickle-shaped extension of blind spot is known as 
Select and explain. 
A. Down's sign, B. Bjerrum's sign, C. Seidel's sign, D. Baring of blind spot
C: Seidel's sign
Answer: C: Seidel's sign 
Explanation: Seidel's scotoma: With the passage of time paracentral scotoma joins the blind spot to form a sickle shaped scotoma known as Seidel's scotoma. Ref:-A K KHURANA; pg num:-219