I was diagnois with floaters by my doctor in april 2012. today about an hour ago i was in the kitchen and suddenly and dark cloud appeared in front of my right eye, i could not see anthing with that eye. i rubbed my eye a couple of times and after

Temporary ?blindness: This require immediate attention by your doctor. Depending on your age and condition this may reflect a possible "transient ischemic attack" or other serious condition . See your doctor asap.

Sudden vision loss…: Requires urgent attention. Hopefully you went to the er or saw an ophthalmologist today. The sudden loss of vision in one eye suggests retinal detachment, central retinal artery/vein occlusion, optic neuritis, glaucoma, etc. Do get examined if you haven't already.