Why don't I need a welding mask when I watch a welding video on YouTube?

because there are no actual sparks?
because the brightness of the screen is limited?
why do you not go blind when you look at a painting of the sun?

You should be wearing a mask every time you are around sparks. Even virtual ones. It’s good practice.

@ragingloli is correct “brightness of the screen is limited”.
You aren’t looking at a welding spark, you’re looking at a rendition of a welding spark.

For this reason

How about a virtual welding mask?

For the same reason that you can look at “images of the Sun” on film, in photos and in paintings without shielding: because the dynamic range of the reproduction equipment and media cannot duplicate the ultraviolet rays that cause the damage to our eyes.

Like others say it isn’t necessary.

My dad had a welding and machine shop when I was little. After we got out of school we would get the bus there since my mom also worked there. I was paid in Lego and NES games to go around cleaning. It was a constant fight to not look at the welding. It eventually became instinct. They are about to weld, shield your eyes.

35 years later I still look away when people weld on tv. I know I don’t have to look away but it is burned so deep into me that I can’t help it.

I have had welders flash and it is effing horrible.

In addition to the bright light we normally see, the welder is giving off high intensity (invisible) UV light that damages eyes and skin. A typical camera lens does not pass UV.
In a lab it is possible to work with UV light with no visible light included. You see and feel nothing but 20 minutes later your eyes burn like they have sand in them.
Kids, Don’t try this at home.

The radiation from the actual welding isn’t transmitted by the photo. It’s like looking at a picture or video of a solar eclipse…you see pictures but don’t get the physical effects. For it to impact you would be like putting on the movie Twister and having your house destroyed by the tornado on the screen.

Look at it this way: open up a blank document on your computer and turn the brightness up all the way. This is as bright as your computer screen can go. If it’s not destroying your eyes now, nothing in a video can do it either. The others are correct that what burns your retinas is specifically the ultraviolet light, which is emitted by the sun and a welding arc alike.

Yeah, images on a computer screen don’t really get brighter than showing full white.

Wow, now that was interesting stuff, guys, thanks a bunch!

For the same reason you don’t have to squint when looking at this.

@Rarebear I squinted (involuntarily :-) )

Same reason you don’t need a condom when watching porn.

@Rarebear – But I almost burned my retina looking at a picture of a partial eclipse.

You did not!