I think that my eyes get the sorest with plasma flash burn. I hate to use a #8-9 as trying to follow chalk lines, I can't see them. I now use a number 5 but my eyes are pretty sore after a cutting session. Been wearing glasses all my life and they don't seem to help cut down the effect. Did try wearing my polarized sunglasses to see if they help because they are uv protected but didn't see any help with that either. I think, as has been posted many times, use the helmet and the shade required to get the job done.