Eyelashes fall out normally from time to time, just as hair elsewhere on the body does. But eyelashes can also fall out for other reasons. Wiping your eyes too vigorously can pull out a few lashes, and it’s better to use an eye makeup remover that does the job without the need for rubbing. In addition, heavy mascara can actually weigh down delicate lashes and cause them to fall out, and the pressure of an eyelash curler can pull them out as well.
Other potential causes of eyelash loss include eyelid infections and thyroid conditions. (If so, your eyelashes will stop falling out once the thyroid problem is corrected.) An infection with a mite called D. folliculorum can cause swelling and inflammation of the eyelash follicles. If you're losing hair elsewhere on your body, alopecia areata, an autoimmune condition, may be the problem.
If you are experiencing a dramatic loss of eyelashes, consult your physician or an eyelid specialist (an oculoplastic surgeon), who should be able to figure out what's going on. The new lash-growing drugs all have potential side effects, and I do not recommend them.
Eyelash loss can also occur as a result of blepharitis - an inflammation of the eyelids.