There are a few types of insects that live harmlessly in our eyelashes. They are too small to see with the naked eye. These bugs are parasites that are closely related to spiders and other arachnids. They are referred to as eyelash mites. They live in and around the hair follicle, which is the root of each stand of hair. They eat dead skin cells and find their home in sweat, where a lot of bacteria like to thrive. There's nothing you can do about them, and they have been there all your life.
Demodex folliculorum is the major species that lives in our eyelashes. They measure about .02 of an inch length. They live happily breeding on the skin. They can be found in the largest concentrations on the cheeks, hair and eyebrows. They have stubby legs that hold tightly to the strand of hair. Normally they live only about three weeks, laying eggs and reproducing most of the time.
Demodex brevis are about half the size of Demodex folliculorum. They live in the hair follicle on the tiny sweat gland. These mites are blamed for skin diseases, thin hair and baldness. An infestation is a medical problem and a doctor should be consulted. This is a rare condition.
There are about 65 different species of eyelash mites. We live with them without even noticing them everyday.
The Crab Louse
Pubic lice can spread to the eyelashes during contact. Crab lice are a sexually transmitted disease. If these bugs, which eat skin cells, live in your eyes, you will know because of irritation. They are not visible, but their effects are. The effects are red areas of inflammation around the hair follicles. If you think you may have crab lice, seek medical treatment.
Normal head lice can infect the eyes too. Since they are larger, only barely visible to the naked eye, they are too large to make a home in your eyelashes. They prefer living in larger regions of hair like the head. At times of infestation on the head, head lice may venture to the eyelashes, but cannot make a home there. Take steps to remove head lice, being careful of the eyes.