Brian, one thing that I find helpful with TIG welding is to get my face close, far closer than I would for stick welding. I am both nearsighted and have presbyopia, but I find that I can see better if I take my glasses off and get up close. Others talk about using magnifying lenses in their welding hoods - I've tried one, but never got it to where I thought it was helpful.
Oh, another thought - when it comes to tacking those blades in place, you might use "flash tacks" - relatively high amperage, electrode positioned very close to (< 1/16" from) the joint, good sharp electrode, no filler. Get it positioned, then get on and off full pedal - maybe 1/3 of a second total, if that much. What you are after is a quick burst that creates a very small fusion tack.