thank you joni , that was very sweet , I realy only asked about the side effects because my daughter brong up the fact that my eyes got bad and needed glasses after I got turned on to o2 , and her new baby has eye problems because of o2, but thats because his eyes wernt developed yet , mine because of age Im sure , I knew when I wrote it it would cause a stir because so many people use it , it works, and its great cause apparently there arnt any side effects to speak of. I know I would be lost without it now because I dont use Imitrex and such, but what is sacred to me Is my sight , and my lungs . Thought if anyone knew of side effects from 02 this is the best place to ask, but if you told me my right arm would fall off if I used high flow o2  I would continue to use it , but don't mess with my sight or lungs . Having said that I smoked for  30 years just quit a year and a half ago . So ... by the way it didn't change the Ha . but chomping on this nicatine gum makes the shadows worse .LOL. just curious have you ever tried it or why don't you use it .I did pm a couple of great guys and they were so helpful I realy can't thank them enough , awesom guys!