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
A 25 year old male presents with painless sudden loss of vision, ocular and systemic examination is not contributory. What is probable diagnosis – 
Select and explain. 
A. Retinal detachment, B. Eale's disease, C. Glaucoma, D. Cataract
B: Eale's disease
Answer: B: Eale's disease 
Explanation: Both Eale's disease and Retinal detachment are causes of painless sudden loss of vision, however Eale's disease is a much more common cause than RD in a young male. Ocular and systemic examinations in both the conditions may be normal.