I have very low iron, is this causing my eyelashes to fall?

Look at thyroid: Generally, thyroid levels being low will reflect itself as hair loss of eyelids and brows....Must look at t3, (liothyronine) t4, tsh, anti-thyroid antibodies and reverse T3 (liothyronine) levels.

Not likely cause: Low iron itself does not affect the eyelashes. Malnutrition, hypothyroidism, trauma, psychiatric disease, lid disease, and other issues are common causes.