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 is an ocular emergency ? 
Select and explain. 
A. CRAO, B. Optic neuritis, C. Acute congestive glaucoma, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Ans. is 'd' i.e., All of the above Ocular emergencies include those conditions that result in acute, severe pain in association with sudden vision loss, or that may lead to vision loss if left untreated; and traumatic conditions that affect globe or adnexa. Comon ophthalmic emergencies are :- Acute congestive glaucoma Ruptured globe Ulcerative or traumatic corneal diseases Optic neuritis Hyphema Endophthalmitis Acute blindness Orbital cellulitis Eyelid or conjunctival laceration Central retinal aerial occlusion (CRAG) Anterior lens subluxation Retinal detachment