There are some harmful UV rays that can injure the surface and mucous membrane of your eyes, and this is known as "arc eyes". When you notice uncomfortable pressure in your eyes, and it's slowly increasing, this could be a big symptom of the arc eye. Besides that, if you start to feel that there's sand in your eye after welding or having difficulty looking at bright lights, these are also symptoms of arc eyes. You should contact an eye specialist as soon as you notice these symptoms.