Call an ophthalmologist and go see him. Now. It's serious enough that you need a pro opinion.

I had something like that happen last year. It started as I walked to work from the parking lot. With every step I saw a bright flash in the center of the eye. Rapid eye moves did the same. Later the flashes stopped but there was this gob floating around in my vision that wouldn't go away. It was like when I last had ointment put in my eye, a greasy blob that moved around and gradually went away. Except this didn't go away.

When I called the eye doc's office and described what was happening, they said come in now, we will make room for you in the schedule.

What happened to me was that I got older. Eventually every one does. What the doc said was that the vitreous (the clear filling) of the eye, with age, converts to a liquid. From the center out. You wind up with a shell of material left coating the retina. This can tear loose instead of gracefully liquefying.

The tearing is serious, the retina can be damaged. Bright flashes are a symptom of pulling on the retina. Damage is better caught sooner than later as later is always worse. edit: if the retina is damaged it can propagate even though the initial problem is over.

Meanwhile those loose bits float around until they dissolve away, never completely disappear. They can drop to the bottom but rapid eye movement will stir them up. Driving will do that.

YOU REALLY NEED A CHECKUP with an ophthalmologist. Have somebody drive you cause the Eye Doc will dilate your eyes.

edit2: In my case old means 48-49, but the doc said that varies.