Why Do We Have Eyelashes?

Long, lush, and lasting eyelashes are the epitome of beauty these days.  However eyelashes have actually been an icon of beauty since before Cleopatra’s made the big screen.  But what, besides beauty, is the function and purpose of these short/long hairs along our eyelids? Why do we have them, if for no other purpose than beauty?

What I have always heard is that they are attached to the edge of our eyelids, so as to protect our eyes from dust, particles of debris, and bacteria that float in the air.  Recently Dr. Hu, from the Georgia Institute of Technology, has had a break through with the actual physics of our eyelashes- correcting that myth! Through an experiment involving false lashes, various mammals, a wind tunnel, and an eye sized dish of water, Dr. Hu found that our eyelashes are about “…1/3 the size of the eye itself” (SMV). Which is a ratio that is consistent amongst every species tested.  This 1 to 3 ratio turned out to be the PERFECT length to divert air flow toward our eyes, and prevent our eyes from drying out.  How could our eyelashes possibly prevent our eyes from drying out?  Well not only do they divert the air containing possibly harmful debris, but our eyelashes also keep moisture from evaporating out of our eyes!  According to Dr. Hu, “…changing airflow around the eye is so important that, from elephants to rabbits, the proportion of lash length to eye width does not change” (The New York Times).  However if eyelashes are too long, they will do the exact opposite of their now understood purpose; they would direct air towards the eye.

Why then are long lashes a huge part of defining beauty in society?  Women go through hoops to get longer lashes: mascara, lash curlers, and even gluing false lashes to their eyelids.  But do the long lashes we strive for result in health defects or other issues with our eyes?  Hair restoration surgeon, Dr. Bessam Farjo, says that persistently wearing false lashes has the potential to seriously damage your actual eyelashes (Daily Mail).  Dr. Farjo deals with patients with damage to their eyelashes more commonly than you would think.  Another article from Daily Mail, reaffirmed that longer lashes have a harmful effect on the eye.  It is because of evolution that our eyelashes have grown to the perfect length to protect our eyes. In the wind tunnel experiment with longer fake eyelashes than 1/3 the size of the eye, the “…airflow [flowed] directly onto the eye surface, meaning it was hit by more particles and also tended to dry out more” (Daily Mail 2).  Dried out, more vulnerable eyes can eventually damage your eye sight.

So, not only do our eyelashes provide another level of beauty, but also provide us with the correct conditions necessary for our eyes to function properly and healthy.

2 thoughts on “Why Do We Have Eyelashes?

  1. odh5019

    My younger sister and I are identical, or so we’ve been told, except for our eyelashes. So this interests me because she has abnormally long and thick eyelashes, while mine are average and much more proportional to me eyes. This has always been something I was jealous that she had, but from the research you gathered is this actually bad for her. Is it more damaging to her eyes that she has large eyelashes. In my own research I see that you are correct that longer eyelashes funnel air and dust particles towards the eye. So I wonder what my little sister can do about her biologically larger eyelashes and how they cause her dry and irritated eyes.

Comments are closed.