This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Trauma, Subject name: Ophthalmology
Not a sign of blunt trauma? 
Select and explain. 
A. Sphincter tear, B. angle recession, C. Corneal perforation, D. Retinal dialysis
C: Corneal perforation
Answer: C: Corneal perforation 
Explanation: Rings of Trauma: Hidden signs of Blunt trauma 1.Central Iris: Sphincter Tear 2.Peripheral Iris: Iridodialysis 3.Anterior Ciliary body: Angle recession 4.Separation of ciliary body from scleral spur: Cyclodialysis 5.Trabecular Meshwork: Trabecular Meshwork tear 6.Zonule/ lens: Zonular tear with possible lens subluxation 7.Retinal Dialysis: Separation of Retina with Ora Serrata