mcostello: Practice carrying a uniform puddle first, when You can, start adding filler and trying to make a uniform bead. Keep the hot end of the filler rod in the argon, but far enough from the arc so it doesn't melt. In the old days they used to teach oxy-acetylene welding first, puddle alone then filler. Once this was mastered the rest follows more naturally.
Hello mcostello, sometimes people will mistakenly believe things are too dark, so they will try to go with a lighter shade in order to "see" better. Instead they will actually experience more glare from the arc and it is harder to see the puddle, it's edges, and what is happening to it with regard to size, crown, flatness, or being concave. I hope that you aren't experiencing this as opposed to the issues you believe to be related to the condition of your eyes. If you can, see about checking out different manufacturers shaded lens, not all specific shade number lens give the same view to the welder. You may have read some of the threads on the forum discussing "cool blue" lens, gold lens, and other types of shaded filter plates, all of these give the welder a distinct and different perspective on how the weld looks as it's being done. Good luck and don't give up, sometimes it just takes some persistence and patience. Best regards, aevald