I'm opening myself up for some great smart ass responses, but here goes anyway; I got a deal on a 140 amp Lincoln MIG welder and picked up the accessories at HF including an auto darkening helmet. I have had three sessions (using FCAW to save the gas) of about 15 minutes each. After each time, my eyeballs ache for a longer period than the last time. I made hood filter darkening adjustments, and practiced with thinner material to reduce the arc each time. Still the eyeball ache lasted longer each time. I searched the problem on the net, and could only find info on Welder's Eye, or Flash Burn. Mine feels like I got punched in the head along with sensitivity to light. No redness, itch or surface burn. The eye doc says he can't find anything wrong, and put me on steroids for a couple weeks to reduce possible swelling. I researched the HF auto darkening helmet too, and didn't find much trash talk there. Anyone hear of or experience anything like this? The doc says I can give it another try in a couple weeks, but I'm not sure what variable to change next. I only have one old wrinkled up lab rat to test on, and I'd hate to blind myself, er... it by screwing around here.