Sometimes an eyelash grows inward so as to impinge upon the front of the
eyeball, or even to extend between this and the eyelid. The condition
exists in _entropion_ but _trichiasis_ is rather the deviation of one or
two cilia by reason of their false direction, individually. It may occur
as the result of a pre-existing inflammation affecting the edge of the
lid and the follicle, and the offending hair is not only badly directed
but small and shrunken as well. On this account it is not always easy to
recognize it, and accordingly in cases of conjunctivitis without
apparent cause it is well to examine carefully with the aid of oblique
focal illumination.
_Treatment_ consists in pulling out the offending hair with ciliary
forceps, avoiding bending it lest it break off short and become at once
more irritating and more difficult of extraction. In case the hair grows
anew in the same direction extract it anew and destroy its root with the
electric cautery.