Eyelashes fall out due to illness, allergy, age, trauma, improper care and improper diet, according to Life123. Infections and mites can also make eyelashes fall out, the source adds.
Thyroid issues and immune system diseases are two medical conditions that can lead to eyelash loss, according to Dermatology Clinics of West Virginia. This source also explains that allergies to mascara can cause itchiness, redness and swelling of the eyes in addition to eyelash loss.
Life123 mentions that as people age, hair thins throughout the body, affecting the eyelashes. Continual rubbing of the eyes or intentionally pulling on the lashes also result in loss of eyelashes, according to Life123. Women who fail to remove eye makeup prior to going to bed run the risk of eyelash loss as do people who don't consume the proper nutrients in their diets, such as protein, according to Life123.