A 27-yr male presents with a sudden, painless loss of vision. His ocular and systemic history is unremarkable. The most likely diagnosis is:

Eales' disease: It is an idiopathic inflammation of the peripheral retinal veins. It is characterized by recurrent vitreous hemorrhage; so also referred to as primary vitreous hemorrhage. It is a bilateral disease, typically affecting young adult males. The common presenting symptoms are sudden appearance of floaters (black spots) in front of the eye or painless loss of vision due to vitreous hemorrhage. 4 stages of clinical course: Stage of inflammation Stage of ischaemia Stage of retinal neovascularization Stage of sequelae Treatment: steroids, laser photocoagulation, vitreoretinal surgery. Ref: Comprehensive Ophthalmology by A K Khurana, 4th edition, Page 254.