Distichiasis, or double eyelashes, is a rare condition where you have two rows of eyelashes. The second row might include a single lash, a few hairs, or a complete set.
Compared to normal lashes, the extra lashes are usually thinner, shorter, and lighter.
Typically, distichiasis affects all four eyelids, but it can show up on just one lid or the lower lids. The extra lashes come out of the meibomian glands on the edge of the eyelid. These glands normally produce an oil that coats tears, which stops them from drying up too quickly.
You might not have any symptoms, but if you do you might experience:
- sensitivity to light (photophobia)
- irritation of the cornea
- droopy eyelids (ptosis)
In most cases, distichiasis is congenital, which means it’s present at birth. It can be caused by a genetic mutation that’s linked to heart problems.
You can also get distichiasis later in life if your eyelids are inflamed or injured.
In this article, we’ll explore the causes, risk factors, and treatment of double eyelashes.
Distichiasis can be inherited or acquired after birth. Your symptoms and potential complications will depend on the cause.
Present at birth
The most common cause of congenital distichiasis is a rare genetic mutation of the FOXC2 gene on chromosome 16. This gene helps lymphatic and blood vascular development during embryonic growth.
Scientists aren’t sure how this genetic mutation causes double eyelashes. However, congenital distichiasis is usually part of a rare condition called lymphedema-distichiasis syndrome (LDS).
LDS involves double eyelashes and lymphedema, or fluid accumulation in the body’s tissues.
The fluid, or lymph, leaks from the blood vessels and into tissues. The lymphatic system normally drains and filters this fluid through tubes called lymphatic vessels.
But if the lymphatic vessels aren’t working properly, the fluid accumulates in the tissue and causes swelling. People with LDS usually experience swelling in both legs.
In LDS, the lymphatic vessels might be:
- functioning incorrectly
LDS is also associated with other conditions, including:
- early onset varicose veins
- cleft palate
- structural heart abnormalities
- abnormal heart rhythm
Due to the heart defects related to LDS, about 5 percent of people with LDS have congenital heart disease.
It’s also possible to inherit distichiasis without lymphedema, but this is extremely rare.
Developing later in life
Acquired distichiasis, or developing double eyelashes after birth, is less common than the congenital form.
It’s caused by inflammation or injury of the eyelid. Common causes include:
- Chronic blepharitis. Blepharitis is eyelid inflammation caused by a skin or bacterial condition. Symptoms may include excessive tearing, dryness, itching, swelling, and burning.
- Ocular cicatricial pemphigoid (OCP). OCP is a rare autoimmune disorder that causes chronic or recurring conjunctivitis. This leads to eye irritation, burning, and swelling.
- Meibomian gland dysfunction (MGD). In MGD, there’s abnormal discharge and hypersecretion from the meibomian glands. The glands are also inflamed.
- Stevens-Johnson syndrome (SGS). This is a rare reaction to medication or an infection. It causes chronic inflammation of your skin and mucous membranes, including your eyelids.
- Chemical injury. A chemical burn on your eyelids can cause severe inflammation.
Genetics is the biggest risk factor for congenital distichiasis. You’re more likely to inherit the condition if one of your parents has it.
In fact, about 75 percent of people who have LDS have a parent with the disorder.
Acquired distichiasis, on the other hand, is caused by certain conditions. These conditions are associated with:
- Eyelid inflammation. You have a higher risk for inflamed eyelids if you have seborrheic dermatitis, or dandruff on the scalp and eyebrows. Other risk factors include allergic reactions, rosacea, bacterial infections, clogged oil glands on your eyelids, and eyelash mites or lice.
- Being female. Females are twice as likely to develop OCP.
- Older age. OCP and MGD are more common in older people.
- Wearing contacts. Using contact lenses is a risk factor for MGD.
- Certain medication. People who take glaucoma medication are more likely to develop MGD. Pain relievers and medications for gout, seizures, infections, and mental illness may also cause Stevens-Johnson syndrome.
- Weakened immune system. Having a weakened immune system increases your risk for Stevens-Johnson syndrome.
If you have these risk factors, you’re more likely to develop a condition that causes distichiasis.
Generally, if you don’t have symptoms, you won’t need treatment. But if you do have symptoms, treatment will focus on managing them. It might also include removing the extra eyelashes.
The best treatment depends on the number of extra lashes and your symptoms. Options include:
Lubricating eye drops
In mild cases, lubricating eye drops can relieve eye irritation. This extra lubrication works by protecting the cornea from extra lashes.
Soft contact lenses
Like lubrication, soft contact lenses provide a layer of protection.
To prevent complications, be sure to use contact lenses properly. An optometrist or ophthalmologist can explain the best practices for wearing contact lenses.
Epilation involves removing the lashes with an electronic device called an epilator. It physically plucks them out.
However, the lashes usually grow back in two to three weeks, so it’s a temporary treatment. It’s only recommended if you have a few extra lashes.
Cryotherapy uses extreme cold to destroy the eyelash follicles. This method is ideal if you have a lot of extra lashes.
While cryotherapy has long-lasting results, it can cause:
- loss of nearby eyelashes
- thinning of the eyelid edge
- eyelid scarring
- lid depigmentation
Electrolysis, like epilation, is best for removing a small number of eyelashes.
During the process, a needle is inserted in the eyelash follicle. The needle applies a short-wave frequency that destroys the follicle.
Lid splitting is a type of eye surgery. The eyelid is split open, which exposes the eyelash follicles. The extra eyelashes are individually removed.
Sometimes, lid splitting is used with cryotherapy or electrolysis.
Argon laser thermoablation
In this treatment, argon laser burns are repeatedly applied to the lash follicles, which destroys the follicles.
You might experience mild discomfort and increased tear flow during the procedure.
Being born with double eyelashes often occurs with lymphedema-distichiasis syndrome (LDS), which is caused by a rare genetic mutation. The condition is linked to congenital heart defects, so it’s important to monitor your heart health if you have LDS.
It’s also possible to develop distichiasis after birth if your eyelids become inflamed.
If you have eye irritation or discomfort, a doctor can help you determine the best options for treatment.