If you are lucky it happens slowly, you will see the curtain across your field of vision. Then you will need extremely urgent surgery to restore what is left of your vision. It is not only a matter of getting to the hospital quickly, but also of doing it gently, since any motion of your eyeballs or shaking of your head could speed up the detachment.
But you could also wake up blind, which is pure horror, especially if it happens in both eyes overnight.
Get t o an opthamologist ASAP! A possible retinal detachemnt is nothing to fool around with. My husband had floaters we waited a month to see a Dr. and he had to have immediate surgery the next day. If scar tissue develops less chance of a good reattachement and greater possibility of vision disturbance. My husband is practically blind in the eye now. He stated at it's worst it was as though a curtain was falling. And basically that is the top part of your eye falling in to the line of the optic nerve, the part that sends the signal to the brain so you can see. Good luck, and remember the best time to correct it is immediately