How tear-ible!

Over 20 million Americans have dry eye disease, which means that their eyes don’t produce enough tears or their tears evaporate too quickly.

Dry air, wind, certain autoimmune diseases, medications like antihistamines and decongestants, too much screen time, vitamin A deficiency and contact lenses are often to blame.

Dr. Ashley Brissette, a board-certified ophthalmologist and eye surgeon at Kelly Vision in NYC, suggests that there’s a scarier, overlooked cause of dry eye — microscopic pests living in our eyelashes and eyebrows. These eight-legged freeloaders are known as eyelash mites or Demodex.

“While they are typically harmless and almost everyone has these,” Brissette told The Post, “an overgrowth of these mites, which feed off of the bacteria that lives on our lashes, can lead to conditions like blepharitis, which causes eyelid inflammation, redness, dry eye, styes, itchy eyes and irritation.”

Before you get out the Raid and make things a whole lot worse, Brissette reveals how to combat these small — and mite-y — intruders.

This may come as a surprise, but most people naturally harbor a tiny population of these parasites in their hair follicles and sebaceous glands.

Your scaly roommates, which measure up to 0.4 millimeters long, mate on your face as you sleep.

That’s disrespectful and disgusting, but generally unproblematic, unless there are too many of them.

Proliferation can happen with a compromised immune system, certain skin conditions and poor hygiene like sharing towels or cosmetics.

Symptoms of infestation include itchy red eyes or eyelids, crusting on the eyelids, irritation, dry eye, styes and even eyelash loss.

“The mites can cause distention of the eyelash follicle and cause natural lashes to fall out,” Brissette said. “This is the most distressing issue for most patients.”

Styes, particularly when chronic or recurrent, are also upsetting because they are visible, uncomfortable and can take weeks to go away.

Meibomian glands produce the oily layer of the tear film, which helps keep eyes lubricated and comfortable.

Mite overgrowth can cause inflammation of the eyelids, disrupting the function of these glands.

“This leads to inflammation on the surface of the eye and a reduced ability to keep the eyes properly lubricated,” Brissette explained.

“The inflammation can also impair tear production and affect the eyelids’ ability to spread tears evenly across the eye, further exacerbating dryness.”

Dry eye sometimes feels worse in the summer due to air conditioning, increased exposure to environmental allergens and poor air quality from things like wildfire smoke.

Sufferers often complain of a stinging or burning feeling, red eyes, a scratching sensation, blurry vision and sensitivity to light.

The prescription eye drop Xdemvy can eradicate the mites. It’s typically taken twice a day for six weeks.

“You also need to be washing the eyelids daily with an eyelid-formulated cleanser,” Brissette said.

“This gets rid of the mites, as well as the bacteria and debris that they feed off of, to prevent them from recurring.”

Brissette recommends Purifying Foam Cleanser from Daily Practice by Dr. B.

In fact, it’s important to wash your eyelids with a cleanser every day to prevent problems. Yes, daily.

It’s a mite-y ask, but worth the effort, Brissette said.