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
First investigation to be done in Hyphema is 
Select and explain. 
A. Slit lamp examination, B. B scan, C. Tonometry, D. Funduscopy
C: Tonometry
Answer: C: Tonometry 
Explanation: First investigation to be done in Hyphema is Tonometry to detect raised Intraocular pressure.