Whenever you see someone with exceptionally long eyelashes that aren't false, it could be the sign of a specific congenital. Every time you see someone with exceptionally long eyelashes, which aren't false, it could be the sign of a specific congenital condition they have, a medication they're taking for a serious medical condition, or because their parents also had long eyelashes. Aesthetically, long eyelashes have been a symbol of beauty for many centuries. Psychologists explain that long eyelashes create a contrast between the eye and the eyelid, making the eyes visibly larger and, therefore, more attractive.
Biologically, eyelashes protect our eyes from dirt, dust and other particles in the air and the environment. Eyelash length is influenced by genetics, but other factors can also affect it. Having long eyelashes, regardless of gender, is a sign of good health. We see those with long eyelashes and healthy, flowing hair, and we associate these traits with overall health and well-being.
If both parents have long eyelashes, you have a high chance of inheriting them because of a mutation in the FGF5 gene. Sometimes, on those rare occasions, there are no additional symptoms and people in the same family have abnormally long eyelashes as a trait. Some scientists believe that if eyelashes have any real function, it is to diffuse airflow that could threaten to dry out the eyeball, and that their length is generally determined in relation to the size of the eyeball itself and not to the gender of the mammal to which they belong. However, it doesn't necessarily follow that a person with long eyelashes has one of these conditions.
To try to better understand what was happening, they took DNA samples from people with trichomegal eyelashes and compared them to the DNA of family members with shorter eyelashes. However, more recent research points to the idea that long eyelashes are valuable because of the illusion they create of wide eyes and gazing eyes. My brother now has two young children with ornate eyelashes, and for what it's worth at press time, at least their eyelashes haven't met the same grim fate as their father's. Even so, eyelashes have managed to become one of the few types of female body hair that falls into the category of “good, emphasizes” and not “bad”, removes one and, for centuries, we have been imagining the presence of long, dark eyelashes to represent feminine beauty at the highest level.
Men with eyelashes longer than this were considered less attractive, and women with short or newly existing eyelashes were considered the least attractive. In the past, long eyelashes were considered an external sign found in children with allergic diseases. Similarly, the only facial difference between Robin Hood's incarnation at Disney and his female counterpart, Maid Marian, was, you guessed it, his black, fluttering eyelashes, and there's a multi-billion dollar industry based on the (strange) idea that when you add eyelashes to your car, you suddenly have a female car. As such, this is what is known as a recessive trait, since the body needs two copies of mutated genes to obtain long eyelashes.