i have this problem occasionally. i tape a shop rag to the top of the welding helmet and let it hang down to the middle of my head. this removes any light from behind hitting the view window.

to help see the weld puddle get your head on a right angle to the weld torch and actual weld area. then pull the weld torch towards you. this will help you see the puddle and the weld joint you are welding. it also gives you a good view of the amount of stick out you have when welding. more, to much, stick out = less penetration and power into the weld making poor welds.
i also like to steady the weld torch with my free hand when welding. this will help from wandering off the weld joint and maintain proper stick out when welding.


i remember my welding class when i went to votech college for autobody classes. the teacher took 2 pieces of thick steel at right angles to each other. he set the welder to get minimal penetration. them we had to lay a 2" bead on the joint. the teacher put the 2 pieces in a vice and snapped the 2 pieces apart by hitting with a hammer on the opposite side of the weld. because there was low power you only got a little penetration.if there was penetration it would remove a nugget of steel from the bottom plate. you can also see the amount of weld penetration on the other piece when you look at the weld nugget. if you were off the joint slightly you wouldn't get any penetration on both pieces of metal and it would be easily seen if you looked at the snapped joint. you couldn't weave between the 2 metal pieces it had to be a single bead straight weld.
to pass the class you had to have 1 3/4" of perfect penetration of the 2" weld. it took me a while to accomplish this task.
this is a good exercise to improve your welding skills and help you see the weld puddle when welding.