• Question: Why don't eyelashes and eyebrow hairs continue to grow unlike our hear on our heads?

    Asked by equivalenttoeinstein804 to Anil, Blanka, Cees, Emma, Mike on 26 Jun 2012.
    • Photo: Emma Trantham

      Emma Trantham answered on 26 Jun 2012:

      Great question 🙂

      Our hair actually doesn’t just keep getting longer and longer. What actually happens is that it grows in stages.

      Stage 1
      This is the growing stage. The cells at the hair root are dividing rapidly and so the hair gets longer and longer.

      Stage 2
      This is where the hair follicle producing the hair is switching from producing new cells to the resting stage (stage 3).

      Stage 3
      This is the resting stage. The hair follicle is not doing anything and you now have your full length hair. (At some point after this the hair will be shed).

      The reason that our eyelashes and eyebrows don’t grow as long as the hairs on our head is that Stage 1 in our eyelashes/brows is much shorter. The hair follicles on our head are in Stage 1 for 2-3 years (sometimes more) but the hair follicles on our head are only in Stage 1 for a few months so the hairs don’t get as long.

    • Photo: Blanka Sengerova

      Blanka Sengerova answered on 26 Jun 2012:

      Love the nickname!

      I have to say that I don’t really know. Maybe it’s to do with the hair follicles (the thing that the hair grows out of) being stimulated to a different extent to hair on your scalp, but I could be totally off the mark. They do grow because if you shave your eyebrows, they’ll grow back, although slowly (one of the guys in my year at university matriculated – meaning starting uni – without eyebrows as he shaved them off in freshers’ week). And one of my colleagues said that in her home country, they cut of babies eye-lashes to make them grow back nice and thick, but I am not sure what the science behind that is.

      Can any of you others shine a light on this mystery? [Oh, I see now there is an answer from Emma – thanks!]