Eyelash transplants were initially developed to help victims of accidents, such as burns, whose natural lashes had been permanently damaged.
The procedure was first carried out in Brazil in 1999, with just a few surgeons worldwide being able to carry out the operation today.
The surgery is now performed for aesthetic reasons, such as on those who feel they have naturally thin eyelashes.
Or people who have permanently damaged their eyelashes using glue-on fake ones.
The glue can rip out the natural follicles, leaving patients with virtually bald eyelids.
The operation may also be carried out on those with the psychological condition trichotillomania, which causes them to have an uncontrollable impulse to rip out their hair.
Radiotherapy or chemo patients may also benefit.
The transplant can only be carried out on the upper eyelid due to hairs on the lower lid growing straight, and being difficult to trim and curl.
Hair is usually removed from the back of the head, where it tends to be longer.
This is because long hair is easier to thread through the upper eyelid.
The hair is then separated into single follicular grafts.
After the patient's eye has been anaestheised, the grafts are threaded with a curved needle.
A normal eyelid has between 100 and 150 lashes per eye.
In a transplant, 25-to-60 new lashes are added.
Bruising and swelling is normal for a few days after the operation.
It takes around six months for the new lashes to grow to their full length.
Source: Aesthetics journal
