Whether you love or hate your eyelash length, your lash length might be influenced by your parents and ancestors. Cosmetics can artificially lengthen the length of your eyelashes, but your natural lash length is partly influenced by genetics.

If you wonder about your eyelash length and whether you have genetic markers associated with longer lengths, AncestryDNA + Traits has answers.

What Do Eyelashes Do?

Whether long or short, eyelashes protect your eyes by catching dust and debris before they can land on your eyeball. These facial features are key to avoiding injury, irritation, and infection of the eyes. They act similarly to facial whiskers, triggering a reflex if a bug or other small object touches them. Research shows that your eyelashes even play an important role in keeping your eyes well-lubricated. They reduce tear evaporation by up to 50%.

While eyelash length can vary from person to person, they usually grow to 12 mm or less before falling off. Typically, different types of eyelashes are classified similarly to the hair on your head, based on:

• Length
• Fullness
• Curl
• Texture

Because how curly your eyelashes are is determined by the same cells affecting the hair on your head, your eyelash type will likely mimic your natural hair type.

Genetics and Eyelash Length

Eyelash length tends to run in families, and scientists have identified genes associated with it. Certain variations in the FGF5 gene, for example, result in longer hair growth associated with trichomegaly (unusually long eyelashes). This gene regulates the hair's growth cycle, determining how long it grows and when it falls out.

AncestryDNA scientists wanted to know just how much genetics influences eyelash length. They asked over 750,000 people, "What best describes the natural length of your eyelashes?" By comparing their responses and their genetic profiles, the team identified over 820 DNA markers correlating to eyelash length.

That data can further be extrapolated using a polygenic risk score. This statistical tool allows scientists to determine the likelihood of inheriting a trait or condition just based on DNA. In the case of eyelash length, the team concluded that at least 25% of the variation in people’s eyelash length is due to genetics. That means environmental factors, such as your health, beauty routines, and even age, also significantly affect whether you've got luscious lashes or not.

What Else Can Impact Eyelash Length?

Genetics don't control everything about your eyelash length. Like the hair on your head, your eyelashes are affected by your general health and the products you use on them.

Hormones control your hair's growth, and when they're unbalanced, they can affect your eyelashes. Hypothyroidism and hyperthyroidism are both associated with eyelash and hair loss. Menopause in women has also been associated with lash loss. Likewise, a deficiency in certain vitamins, such as biotin, or minerals like iron and zinc, can impact the health of your eyelashes. If you lose lashes too frequently, they may appear shorter because they take about eight weeks to grow.

If you want the look of longer types of lashes and tend to use makeup, curlers, or artificial lash extensions, you might be working against yourself. These products can dry out your eyelashes or lead to breakage or eyelash loss.

As you age, your lashes also change. One study of 179 women of varying races revealed that eyelash length decreases with age. In the 50- to 65-year-old range, the mean eyelash length was 6.39 mm. In the 22 to 29-year-old range, the length was 7.98 mm. The older participants also had lighter and thinner lashes compared to the younger group.

You've got options if you want longer lashes without cosmetics like mascara. Comb your eyelashes daily to keep the follicles unclogged. Apply moisturisers using vitamin E, castor oil, or almond oil to nourish them. You might want to skip makeup for a while to let them grow. A healthy diet can also support healthier eyelashes (and skin and health).

Fun Facts About Eyelashes

The longest lashes ever recorded were a massive 20.5 cm. You Jianxia, from Shanghai, China, has eyelashes that started growing longer than usual in 2015 and have grown continuously since then.

While you might not grow such long lashes, your upper lash line grows more than your lower one. It has larger, deeper roots, allowing lashes to grow longer. Most people have between 90 and 160 upper eyelashes and around 75 on the bottom. The top lashes are usually between 8 and 12 mm long, while the lower ones are just 6 to 9 mm. This size difference allows the lashes to work together, acting as a shield when you close your eyes to keep sweat, dust, insects, and other junk out of your eyes.

All mammals have eyelashes for the same reason. Interestingly, eyelash lengths across species tend to follow similar ratios when compared to eye size. They tend to be approximately 1/3 the width of the eye to provide just the right amount of protection.

Wondering how genetics shape your physical appearance? Take an AncestryDNA + Traits test today to discover whether you have DNA markers associated with common traits beyond eyelash length, such as hair strand thickness, facial hair fullness, and dimples. If you've already taken an AncestryDNA test, review your results now with an Ancestry subscription.