You can see the ophthalmologist in the morning but make sure to have it checked out basically withing abouty 24 hours or so. It is likely a posterior vitreous detachment. The chance of having a retinal tear or detachement it about 5 or 10% roughly. Good Luck.
MJK MD
Just a comment that I had very similar thin crescent shape lights that flashed in top and outer corner of one eye. I, too was worried about retinal detachment. Eye was dilated and examined to see if any retinal tears. Doctor saw none which was good news; he said symptoms indicated that a posterior vitreous detachment may have started - so I can corroborate what Dr. Kutryb has said here. Flashes did not last more than a day or so, but I now have many new floaters....
Dear starvoyager1956,
I would recommend that you seek the care of an eyeMD for this issue. I would call your eyeMD and explain your symptoms. He or she will ask you further questions and determine when an examination is needed.
Dr. Feldman
Sandy T. Feldman, M.D., M.S.
ClearView Eye and Laser Medical Center
San Diego, California
Thanks Dr. Kutryb for your response.