auto darkening helmets

How Auto Darkening Welding Helmets Work

The amount of misinformation there is about auto darkening helmets is staggering considering how simple they are to use. This article is here to set the record straight, explaining exactly how modern auto darkening helmets work and if they’re really safe compared to traditional welding helmets.


Why the Confusion?

When you were a child, did your parents or teachers ever tell you that astronauts could see the Great Wall of China from space with just their eyes? That “fact” actually came from a Ripply’s Believe It or Not cartoon from 1932. The only problem is that in 1932, no one had ever come close to going into space. When mankind finally went to space some 29 years later, the astronauts couldn’t actually see the Great Wall of China. But the myth had become so popular, it continued to be spread well into the early 2000s.

darkening welding helmets

The same concept holds true for auto darkening helmets. When this new technology was first introduced, it had a few issues that led to some misinformation on how it worked. The internet has continued to spread those myths. For this reason, we’ve gone directly to your favorite manufacturers to ask them how their auto darkening helmets work.


You Are Always Protected

One of the biggest myths out there with auto darkening helmets is how their UV/IR protection works. As long as your helmet is from a reputable brand, it will have multiple filters. The first lens is a clear cover that protects the real lens (you can learn more about lens covers here). Behind the protective cover, there is a UV/IR filter that blocks the dangerous UV/IR rays produced by an arc. Then behind that, there are several polarization filters which use a technology called Liquid Crystal Cells (LCC). The filters that use LCC are the ones that darken or lighten when an electrical current is applied.

welding protective lenses

The main takeaway is that the UV/IR filter is completely different from the LCC filters. The LLC filters need power to work, the UV/IR filter does not.

Even if your auto darkening helmet is completely out of batteries, it will still protect your eyes from UV/IR rays. You won’t be able to see very well without power, but the UV/IR filter is always protecting you.


What About “Arc Flash”

The vast majority of auto darkening helmets use sensors to detect light from a welding arc. This is how they know when to tell the LCC filters to darken or lighten. The whole darkening process happens in about 1/25,000 of a second. This prevents you from being “arc flashed” when wearing an auto-darkening helmet. “Arc flash” simply refers to being flashed in the eyes by the bright light of a welding arc (either with a helmet on or off).

When auto darkening helmets first came out a couple of decades ago, their sensors could easily be blocked by smoke residue or dirt as you were working. This would cause the helmet not to darken when you struck an arc, resulting in your eyes being exposed to a bright flash.

auto darkening welding helmet

It’s important to understand these arc flashes, while not fun, do not allow UV/IR rays to damage your eyes (as long as your helmet is on). Again, the UV/IR filter in an auto-darkening helmet is always protecting you. That being said, getting flashed still sucks. It won’t sunburn your eyes, but it’s basically like someone pointing a flashlight right into your peepers. For this reason, modern auto darkening welding helmets are much more reliable when it comes to darkening. For instance, both the Miller Digital Infinity series and the Lincoln Viking 3350 series have 4 light sensors. This drastically reduces the chance of accidentally getting flashed.


Eye Fatigue Is Real

In order to block ultraviolet and infrared rays, the UV/IR filter in a welding helmet aggressively reduces the wavelength range you can see. This gives everything in your vision a green tint while you weld. More and more studies are finding that this green tint makes it harder for your eyes to concentrate on what you’re looking at. This causes your eyes to become fatigued, decreasing your quality of work and motivation while increasing your chances of headaches and long-term eye problems. At the end of a long day’s work, it can honestly feel like your eyes have run a marathon.

The good news is that welding manufacturers are reaching huge breakthroughs in this area. Optrel’s latest helmets have True Color View technology, which significantly reduces the lime green tint and displays much truer, richer colors to help reduce eye fatigue. Miller’s helmets use Clearlight 2.0. Likewise, ESAB and Lincoln have similar technologies in their new helmets.

welding helmet


Go Cheap, Go Blind

When it comes to welding helmets, there are brands that you can trust and brands you can’t. Yes, you can get an incredibly cheap helmet from a brand no one has ever heard of. But there are horror stories of these cheap brands completely leaving out their UV/IR filters. Often they have one or two sensors that can easily be blocked or just stop working over time. And good luck complaining to the manufacturer who’s on the other side of the world for your money back.

That’s why at Welding Supplies from IOC, we only stock manufacturers who’ve proven their trust through incredible quality assurance and decades of experience. It’s also why we pride ourselves on having the best customer service in the industry. When you buy a helmet from us, you have our pros and service experts behind you 100%. Check out our complete collection of auto darkening helmets from the top brands at the best prices here.