your remedies are all wise tails I have welded for over 35yrs. Crushed ice in ziplock bag and 4advil go to bed try to sleep as for the drops at the ER, use it enough and you will go blind that shit desolves the cornea in your eyes sorry about the spelling.ice and rest
I have 30 welders that work for me and anytime any of them have had welders flash this has proven to work in every case.
Put slices of Potato over your eyes, lay back and relax. Burning & pain should be gone or reduced to a tollerable level dependening on the severity. You can repeat as often as you like until all of the buring & scratching pain is completely gone.