Eyelash length is largely determined by genetics, but there are other factors that can also influence it. Trichomegaly is the name given to eyelashes that measure more than 8 mm in the peripheral section and 12 mm in the central section. This condition can be caused by environmental factors, genetic inheritance, and even the mother's diet during pregnancy. Women who consume more olive oil and omega-3 fats during pregnancy have been found to have babies with longer, thicker eyelashes.
The eyelashes are in a growth cycle much like that of the hair on the head, growing at a rate of approximately every three months. However, trimming them back will cause them to take longer to grow back to their original length. Fortunately, modern treatments, extensions, and other solutions for eyelash growth can be prescribed as treatment after a visit with a plastic surgeon or other medical professional. Long, thick eyelashes are a desirable physical feature, revered by many societies and cultures as ideal for both men and women.
Eczema, psoriasis, and certain thyroid disorders can also disrupt the normal growth cycle of eyelashes, causing them to fall out at a faster rate than usual. Eyelash extensions are made from a variety of materials, such as horse hair, mink and synthetic fibers, and are applied by a professional beautician eyelash by eyelash to achieve a very natural and long-lasting look. As such, this is known as a recessive trait, since the body needs two copies of mutated genes to obtain long eyelashes. People who wear makeup on a daily basis should develop a strict skin care regimen that includes using a makeup remover every night and using quality cosmetics that do not cause allergy or further damage to the eyelash follicles.
To try to better understand what was happening, researchers took DNA samples from people with trichomegal eyelashes and compared them to the DNA of family members with shorter eyelashes. After measuring the dimensions of nearly two dozen mammalian eyes, performing a series of experiments in wind tunnels and performing some complex models of fluid dynamics, researchers determined that most mammalian eyelashes measure one-third the length of their eyes, just the right length to minimize the air flow over the eyeball. Short eyelashes are a common physical characteristic that can be due to a variety of possible causes, including hereditary and genetic factors, the use of cosmetics, diseases and ailments, medications, and even aging.