You do not mention how often these occur or for what duration? Are these flashes associated with headaches, an aura or other symptoms? You also do not mention whether these occur with your eyes open or closed.
Sandy T. Feldman, M.D., M.S.
ClearView Eye and Laser Medical Center
San Diego, California
Flashes and Floaters CAN happen after lasik. Usually as a result of a PVD due to the pressure your eye is under as the flap is created. It is much more likely in high myopes. I have floaters post lasik just like you. Here is an article on it.
The flashes last for only a second so I don't believe they are associated with headaches (which I get almost every other day now). They occur anywher from 5 to 10 times a day, it varies. They also occur when my eyes are open or closed. They happen often when I go from a light to dark environment...for example when I come inside from being in the sunlight or when I turn off a light. Also after I have been staring at the computer screen for a while.