Long, artificial lashes are becoming more and more popular, but getting them can be a significant undertaking. While strip lashes may be easier to apply on your own, individual single lashes are applied by a professional where every single artificial lash is attached to your real lashes with a specific glue.

The process takes time, since your upper lid alone has roughly 150 to 250 lashes. So it might be 1.5 to three hours until you're done. Afterward, the lashes must avoid contact with water for 24 hours. Trips to the sauna or the tanning salon are out as well.

Even if everything is done right, things can still go sideways — your lid could get infected.

"It can weep, be painful and itch badly. It's really very uncomfortable, and sometimes it looks weird, too," Christiane Bayerl, director of the Dermatology and Allergology in Wiesbaden in western Germany, told DW.

Contact allergies can develop, which could then turn into eczema in the area around the eyes. While that might not be nice to look at, it's only temporary, Bayerl explained.

Protection, not beauty

But the original point of lashes isn't to look pretty anyway. They protect our eyes from dust particles and other foreign matter, like sweat, wind and precipitation.

Lashes take around four to six months to grow and they "live" for 100 to 150 days. They always grow back, but not necessarily long or voluminous enough for some women. That's where lash extensions come in.

When it comes to making lashes look longer or like you have more of them, you have the choice between silk, synthetic materials or animal fur. In the latter case, the lashes are made of mink fur.

Animal rights activists are strongly opposed to using real fur for cosmetic purposes, especially if it comes from animals that were killed in order to make coats and other garments. Fake lash producers say that they get the tiny hairs from brushing live animals. But that would be difficult with aggressive, snappish minks. 

Import from Asia

Mink-hair lashes are mostly imported from China and South Korea, where animal protection laws aren't as strict as they are in many Western countries. Companies and salons don't have to reveal the origin of their product. In order to find out whether the lashes are made of fur or synthetic materials, customers would have to ask.  

The procedure to attach the lashes costs a pretty penny: €150-220 ($170-248) for the initial appointment. After a few weeks, the fakes will fall out with the natural lashes, at which point you'll need to have a few more attached, which costs roughly €60 for a touch up.

Experts warn against places that offer the initial procedure for less than €120 though, saying that you should question the quality and competence of those providers.

An alternative: Lash serum

Another method for longer lashes are serums, which you apply to your lashes to make them grow.

"Those substances are related to prostaglandins," Bayerl said. "Prostaglandins are used in medical eye-drops, for example to treat glaucoma. But for those you need to get a prescription."

Over-the-counter lash serums can irritate the eyes. If this happens, you should stop using them immediately. A doctor might use anti-inflammatory medication to treat the irritation.

Very rarely, prolonged use of lash serums can lead to particular infections with more "dramatic consequences", Bayerl said.

One of the potential consequences is that your iris could change color.

"Asymmetric eye colors could develop as a result," Bayerl said. "The pigmentation, the brown color around the eyes, could be intensified. That means that the eye area's fat composition could change, which would not look pretty."

Permanent change?

Whether these rare consequences like a change in iris color are permanent isn't entirely clear yet, since the use of lash serum is a rather new phenomenon, Bayerl explained.

"One case of iris discoloration was presented at our dermatology conferences, and it looked like it lasted for a very long time," she said. "It even appears to be permanent."

Up to 10% of users experience side effects. If you still want to try the serums to get fuller, longer lashes, you can rest easy, though: the unwanted consequences will not affect your eyesight.