Flashing lights???

I've realized everytime I get my period by the 3rd or 4th day I'm q nervous anxious wreck. Recently I became aware of some flashing in my vision. Now I'm pretty sure these have always been there and I've been to my eye doctor twice since noticing them and everything checks out clear (I also have glaucoma and have to go several times a year to check pressures) but I've noticed that during my cycle these lights seem to pick up. Anyone else experience anything like that?