We have hair on our heads, arms, legs, and all over. It's everywhere! There are even hairs on our tongues and inside our noses and ears. Some of these hairs we rarely ever think about, though.
But what about the other hair on your face? We all have eyebrows and eyelashes, for example. Do you give them much thought? Have you ever stopped to WONDER about your eyelashes? What would happen if they grew like the hair on your head?
Since we usually don't give our eyelashes too much thought, you might be tempted to think that they don't grow. After all, you don't need to cut them like you do the hair on your head, do you?
Eyelashes do indeed grow, though, and they help protect your eyes. Technically, your eyelashes are known as cilia, and they help keep dust and debris out of your eyes. When your eyelashes sense foreign matter that might harm your eyes, they trigger a reflex that makes you blink and close your eyes. This defense mechanism is an important way your eyes stay protected.
Because of this important job they play, it's a good thing your eyelashes do grow and replace themselves. Hair on your body grows and rests in an ongoing cycle that repeats over and over again as hairs are lost and replaced. Compared to the hair on your head, the growth phase of eyelashes is very short. In fact, it only lasts about 30-45 days.
In addition, the resting (dormant) cycle is much longer. While the head on your hair rests for a while before it falls out and is replaced, your eyelashes rest for a much longer time and aren't always immediately replaced when they fall out.
This explains why eyelashes seem like they're not growing at all. When they do grow, they grow for just a short period of time and then they rest for an extended period of time. Compared to the hairs on your head, this makes them seem like they're not growing at all!