It might seem surprising, but microscopic organisms can indeed reside on your eyelashes. These tiny inhabitants are a natural part of the human skin’s ecosystem, often living unnoticed. While common, understanding them can shed light on their role and potential impact on eye health.
Understanding Eyelash Mites
The microscopic organisms found on eyelashes are primarily two species of mites: Demodex folliculorum and Demodex brevis. These arachnids are too small to be seen without a microscope, measuring 0.15 to 0.4 millimeters. Demodex folliculorum typically inhabits hair follicles, especially those of the eyelashes and eyebrows. Demodex brevis prefers to live deeper within the sebaceous glands, which are the oil glands connected to hair follicles.
These mites have an elongated, semi-transparent body with eight short legs located near their head, allowing them to navigate the narrow spaces of hair follicles. They are natural inhabitants of human skin, with nearly all adults hosting some population of these mites. Their existence on human skin is a commensal relationship, meaning they benefit without usually causing harm to their host.
How Mites Live and Spread
Demodex mites spend their entire lifecycle on the human host, primarily within hair follicles and sebaceous glands. They feed on dead skin cells and the oils produced by sebaceous glands. At night, these mites emerge from the follicles to mate on the skin surface before returning to lay their eggs inside the hair follicles or oil glands.
The lifecycle of a Demodex mite is relatively short, lasting approximately 14 to 16 days from egg to adult. They develop through larval and nymph stages before maturing. These mites are common, with prevalence increasing significantly with age; nearly all individuals over 70 harbor them. Transmission typically occurs through direct contact with hair, eyebrows, or skin containing the mites, or through shared bedding.
When Eyelash Mites Cause Issues
While Demodex mites are a normal part of the skin’s microbiome, an overpopulation can lead to various issues, particularly around the eyes. This condition, known as demodicosis or Demodex blepharitis, often arises when the mites multiply excessively due to factors like a weakened immune system, certain skin conditions such as rosacea, or poor hygiene. The symptoms of an overgrowth can include itching, burning, and redness around the eyelids. Some individuals may experience a gritty or foreign body sensation in the eye, blurry vision, or crusty, sticky eyelashes.
An overabundance of mites can also lead to inflammation of the eyelids (blepharitis) and, in some cases, affect the cornea (keratitis). A distinct sign of Demodex blepharitis is “cylindrical dandruff” or “collarettes,” waxy, tube-shaped debris found at the base of the eyelashes, indicating mite overgrowth. If symptoms persist, a healthcare professional can diagnose a Demodex infestation by examining the eyelashes under a specialized microscope.
Dealing with Eyelash Mites
Managing Demodex mite overpopulation primarily involves consistent hygiene practices and, when necessary, medical intervention. Regular face washing, ideally twice a day with a non-soap cleanser, helps remove excess oil and dead skin cells that serve as food for the mites. It is also beneficial to gently clean the eyelid area and thoroughly remove eye makeup, as shared cosmetics can contribute to mite spread. Washing pillowcases and bedding regularly in hot water and drying them on high heat can help eliminate mites that might transfer from the skin.
For more problematic infestations, seeking professional medical advice is important. A doctor might recommend specific cleansers or wipes, often those containing tea tree oil, which has properties that can help reduce mite populations. In more severe cases, prescription treatments such as topical medications like ivermectin, metronidazole, or permethrin may be prescribed. Oral medications can also be considered for extensive infestations. Professional in-office procedures, such as specialized eyelid exfoliation, can also clean eyelid margins and remove debris.