When welding, the temperature is so high that in addition to the welding wire or the welding electrode also the metal along the welding seam of the workpiece itself becomes liquid. Workpieces and consumable metal have the same composition.
This is done at about 1,500 C, with a heat source of 3,000 to 4,500°C. This can be by gas welding with gas and oxygen, or with electrodes. My father ‘s first welding station had puissance and nuisance. When the first (mono, black/white) TVs were purchased in the street, he occured image disturbances. It took a long time before we realized why. Later they knew: Miel is welding. (It was resolved, first with custom (more social) work hours, and later with a heavier power connection.)

Arc eye: raw potato

If you look at the welding arc you will suffer from arc eye. This photokeratitis or snow blindness is a form of corneal inflammation by eye exposure to ultraviolet rays. Also looking into the sun(lamp), or sun on snow too long (without adequate protection) cause the same, very painful effect after 1/2 to 6 h.
Therefore, there are screens and helmets with dark glass to weld.
It heals by itself in 1 to 2 days. Try not to rub in your eyes. Get eye drops. Or grate a raw potato and wrap in a damp kitchen towel to put over your eyes. That provides some cooling.