I am having the same problem first the tunnel vision then a pounding headache/migraine. I would also love to know what it is. I have some what figured out that i trigger it when i work out for some reason.

i get it too! i hate it so much. I think for me its cause by slouching or when i work out and do strenuous sports like squash or sit-ups. I think it's some nerve that is being affected somewhere around the neck region. I'm not too sure. The eye doctor I went to doesn't really have much of a clue and this frustrates me. I realise I get it when I'm using the pc or watching television most of the time.

Its probably a migraine. See your doctor though to be sure. I have the same problem.

Any blurred vision and headache can be serious, however if you are older check this out...It could be far more serious...

Caroline

I am 48 and I have been getting the blurred vision problem for 20 years usually about an hour after strenuous exercise (squash) but sometimes only little exercise. In fact I got it the other day while baking biscuits?? Starts with small blurry circle then it gets wider in an arc until it disappears out of my vision entirely, takes around 20 mins and you definitely cannot drive. I found I always got a headache afterwards, and take panadeine now to avoid the bad headache/migraine that might ensue. I had a doctor do tests and only concluded that I was getting the symptoms of a migraine with or without the headache - not much help. I am used to it now, they are much less frequent, only maybe once every couple of years and I still play squash.