Causes of floaters and flashes
Lots of people, particularly older people, get floaters and flashes.
They're usually caused by a harmless process called posterior vitreous detachment (PVD), which happens as you get older.
Sometimes they can be caused by retinal detachment. This is a serious condition where a thin layer that sends signals to the brain (the retina) pulls away from the back of the eye. It can lead to permanent vision loss if not treated.
Floaters and flashes can also happen for no obvious reason.