Distichiasis is a rare congenital condition where you have two rows of eyelashes. The second row of eyelashes can include anywhere from a single lash or a few hairs to a full, complete set. Usually, this second row has thinner, shorter, and lighter eyelashes. Distichiasis most often affects all four eyelids. However, in some cases, people have eyelashes growing from just one lid or just the lower lids. People with a second row of eyelashes might not have any additional symptoms, but some are more sensitive to light, others have irritated corneas or might be prone to getting conjunctivitis.