thank you for the explanation about the O2! That is great to know. My GP couldn’t explain why it worked he related it to a hyperbaric chamber…I saw him yesterday because I needed some relief from the pain and the only thing he would prescribe was prednisone for yesterday and today.20 mg It stop the worst part of my headache within 2hrs. I asked him about Diamox and then he threw out a name of another drug I had never heard of. He said he would look into Diamox. I see him again tomorrow…I have a referral for a neurosurgeon, not sure how long it will take to get in to see him and if he will be the kind to listen? I don’t like taking prednisone but at least I know it does something. He got the report from the optometrist and he though it was significant.