flashing rings of light

I have a similar issue to a previous thread occuring with some differences:

I have experienced rings of light that start out in the center of my area of vision.  The centers are clear with the ring appearing like areas of short black lines with flashing white light.  There is no headache at this point.  The rings are visible in both eyes and with eyes open or closed.

The rings gradually widen into oval or football shapes.  As they widen to the periphery of my vision the flashing white light intensifies. The central vision area is unaffected by the flashing but there are spots where vision is difficult. I would compare this to the spotty vision one might experience when standing up too fast.

This has happened every other day for the last 5 days, at about the same time mid-morning.  The first 2 incidents there was no accompanying headache.  Today I am experiencing some feeling of pressure behind my nose and also a slight band of pressure around the forehead.  In each instance this has lasted for about 1/2 hour after which time the flashing circles disappear out of the far edges of my range of vision.  The general spottiness of vision continues for about another 5 minutes after which my vision returned to normal, but with the headache same as described above.

Is this consistent with ocular migraine symptoms I have seen described or is there some other area of concern I should check out?

[Forum-OD-MP]

YES.  ocular migraine.  classic ocular migraine symptoms.  very UNlikely to be any retinal problem that you need to have checked out.

[mcdonaldwi]

Are there things I can do to avoid or minimize the impact of these?  I can't identify any common trigger, except for general stress level.  I do expereince regular migraines that last over several days and do not respond to OTC pain medications.

I am less concerned after this response, but if it were to reoccur while driving that would be pretty scary!

[Ag-i-doc]

um, yes.  there are things you can do.  medications (like topamax, etc) to prevent the onset of migraines.  you need to be talking to your primary care physician or neurologist.  this is not an "eye" problem...