In the old days before the Auto Darkening Helmets were around it was common for some people to wear some type of Sun Glasses or dark Safety Glasses with side shields under the Helmet.
You would start of with the Helmet open and sort of Rock your head quick and the Helmet would fall and cover your Face. Well sometimes it will not fall when you do that and you end up flashing (seeing the Arc). If it happed enough your Eyeballs are going to feel like some one put Sand in them (You would be feeling tiny Blisters on your Eye).

So some people wore Dark Glasses for that reason and if the Arc starts with out the Helmet down it is possible for hot Metal Splatter/Sparks to hit your Face and Eyes and even with the Helmet in place Hot Metal Splatter/Sparks get inside and gets you.
So wearing some sort of Goggles/Safety Glasses can be a good idea to protect your eyes from flying Spatter/Sparks.

I have worn Glasses since I was a little Kid so I always had some protection. Also although I managed to flash My Eyes with the Arc about as much as My friend who worked with Me I never had an Eye problem from the Flash. I think My Glasses filtered out enough of what ever light causes the little Blister.
But, My Bosses cure for that was no Welding and you lay down with Potato Slices on your Eye Lids.

Also what I am saying above is if you are in the standing position and welding stuff on a table about that is about Elbow height. If you are Arc Welding in other positions more stuff is going to get under the Helmet.

Keep a Fire Extinguisher handy.
And, remember that your clothing can burn.

When I welded the rear Cross Member on the Rear of the Mercedes I was under the Car in a cramped position. I had stopped Welding but there was still Smoke and the Smoke smelled different from the Welding Smoke. It turned out the frayed sleeve of the old Coat I was using had caught Fire. And that is with a Flux Core Welder that does not produce as much hot splatter as a regular Arc Welder.

My Friends frayed around the Pockets Jeans use to smolder sometimes. I wore mixed Polyester and Cotton work clothing that Sears Sold back in the late 1960s and holes would burn through them from the Splatter but I can't ever remember them smoldering like Jeans do.

Also a regular Arc Welder were like sun burn your exposed Skin and especially your Neck between your collar and the front of your Chin.

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84 300D, 82 Volvo 244Gl Diesel