Oldpilgram, My eyes are as old or just about as old as yours. I started welding back is 1965 aboard a large grey ship. I know I will get beat up on this but I feel you need to see good about an inch around the weld puddle. If you can't use a lighter lens. When I was working I used a #10 lens for everything. Then I started having problems seeing doing Mig stainless. I went to a #9. A lot of the stainless was 18 gauge some 16 gauge.With low amps and the lighter gauge stainless I went down to a #8 so I could see the weld. Even for Low amp stainless tig I used a #8 lens. If you can't see, you can't weld. You need to see the puddle, if you can't, use a lighter lens. All aluminum tig was done with a #10 lens, low amps or high amps. If I remember correctly all mild steel mig was done with a #10. The low amp stainless gave me the problem. If you can't see go a shade lighter. Another poster on here said never go below a shade #9. Why is a #8 made if there was not a demand for it and if it was not safe to use if conditions required a lighter shade. I still stick weld with a #10 and if I can't see when doing something else I will go to a lighter shade until I can see. You are the man looking through the lens, you will be able to see if it is too light. That is my experience and two cents worth. Don't ruin your eyes. I have not seen any weldors working with a seeing eye dog.