One of the main things that indicate the possibility of retinal detachment is when a person sees "floaters" in their line of sight. These look like specks of debris, hair or spots that seem to be floating in air.  If the detachment is happening in a specific eye, that eye may notice flashes of light. It can also seem that a curtain has begun to close on the visual field of an affected eye. There may also be some shrinking of vitreous, the gel-like material that fills the eye. Seeing spots of floaters for a few seconds does not necessarily warrant a diagnosis of a detached retina. If floater persist, treatment is likely needed.