Eyelash Facts

A study published in the Journal of the Royal Society Interface reports that eyelashes divert airflow to prevent drying of the eyes and protect against airborne particulates.

Twenty two species of mammals possess eyelashes of a length one-third the eye width. Wind tunnel experiments confirm that this optimal eyelash length reduces both deposition of airborne particles and evaporation of the tear film by a factor of two. This happens because of the incoming flow's interactions with both the eye and eyelashes.

Another study found that growth of eyelashes occurs in response to exposure to allergens. Children with allergies have ten percent longer and denser lashes than those without allergies. Allergens trigger mast cells within the inside of the eyelid to release prostaglandins that promote hair growth, which presumably protects the eye. If models only knew their long lashes make them look like they have allergies.