What Are Monolids (Epicanthal Folds)?

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The term “monolid” is a colloquial way of referring to an eye that only appears to have one eyelid fold, rather than a double lid. Monolids are common in people of East Asian heritage and are also associated with some diseases and conditions, including Down syndrome.

Also know as an epicanthal fold, monolids are a piece of skin on the eyelid that runs from the nose to the eyebrow. It gives the eyelid the appearance of having no crease. In some cases, it can make the eyelid more prominent and droopy, creating a more narrow appearance in the eye.

Monolids are perfectly normal and do not affect vision on their own. If a monolid is caused by a medical condition like Down syndrome, it could be linked with other eye troubles.

close-up of eye

Kaneko Ryo / Getty Images

Anatomy

To understand monolids, it’s helpful to know a bit about eye anatomy. Human eyes have both upper and lower eyelids. The upper and lower eyelids meet at the corners of the eyes, an area known as the canthus. Most people have a visible crease in the upper lid, which gives the upper eyelid the appearance of having two sections. This is known as a double lid.

However, not everyone has this. Monolids, which have no crease, are common in people of East Asian descent, particularly Chinese or Korean heritage. Without a crease, monolids appear as just one section. About half of Asians have a monolid.

People who have a monolid have an epicanthal fold. This piece of skin covers the inner corner of the eye, reducing or eliminating the appearance of an eyelid crease. Monolids can make the upper eyelid appear puffier or give the appearance of narrow eyes.

Causes

Monolids are part of the normal variation of human appearance. They are usually caused by your genetics but can also be caused by medical conditions.

Genetics

People of Asian heritage are the most likely to have genes that cause an epicenthal fold, and therefore a monolid. Specifically, people of Chinese, Korean, Mongolian, and Japanese heritage are most likely to have a monolid. When East Asians do have an eyebrow crease, it’s often less prevalent than the eyebrow crease of caucasians.

Scientists don’t fully understand why Asians developed monolids. There is a theory that the monolid gave an adaptive advantage to ancient Asians living in cold and windy climates like Mongolia by protecting the eye. However, scientists don’t know for sure that this is why Asians have a monolid.

Medical Conditions

In addition to people of Asian descent, some medical conditions can cause a monolid in people of any ethnicity. These include:

  • Down syndrome
  • Fetal alcohol syndrome
  • Turner syndrome
  • PKU syndrome

There is also a condition known as blepharophimosis syndrome, which is characterized by a monolid, narrow eyes, and an epicanthal fold.

Creating a Crease

There is nothing wrong with having a monolid, and many people embrace this eye shape. But some others want to give the appearance of having a double lid and wider eyes. This can be done with makeup, adhesives, or surgery. If you are unhappy with your eye shape, you can try these, but remember that monolid eyes are beautiful just as they are.

Makeup

Asian makeup artists have their own tips and tricks to make monolid eyes look bigger or give the appearance of a crease. Eyeshadows and eyeliner can be used to draw attention to the eyes, making them more of a focal point on the face, even if they are narrow. Using bright colors, particularly on the inner eye, can help make a monolid eye pop, makeup artists say.

Tape or Glue

Some people with monolids choose to use tape or glue to give the appearance of having a double lid. The adhesives are meant to create an artificial crease in the eye temporarily, giving it the appearance of a double lid or wider eye.

Some people find eyelid tape or glue difficult to use and uncomfortable. The tape can make it more difficult to blink and affect tear production, all of which can have an impact on eye health.

Surgery (Blepharoplasty)

In order to permanently change the look of a monolid, some people opt for surgery to create a double lid. This type of surgery is know as blepharoplasty. The specific type of procedure most often used for people with monolids is double eyelid surgery.

During a blepharoplasty to change the appearance of a monolid, a doctor will create a crease in the eyelid, giving it the double lid appearance, and remove excess skin on the eyelid. This can be combined with a procedure known as ptosis surgery, which strengthens the eyelid muscle, giving a more wide-eyed appearance.

Popularity of Eyelid Surgery

In 2016, blepharoplasty was the fourth most popular plastic surgery procedure in the United States. In Asia, the procedure is even more common—in fact, blepharoplasty is sometimes called Korean eyelid surgery, because it’s the most common surgery in Korea.

A Word From Verywell

It’s natural to be uncomfortable with a part of your body. If you dislike your monolid eyes, try to remember that having an eyelid with no crease is entirely normal and beautiful. Of course, that’s not always easy with traditional beauty standards and a modern emphasis on caucasian beauty standards.

If you want to change the appearance of your eyes, temporarily or permanently, be sure to consider the medical and emotional benefits and drawbacks. Remember that there’s no medical reason to change the appearance of your eyes—having a monolid won’t affect your vision, for example.

Ultimately, you’re the only one who can decide how comfortable you are with your eye shape and whether embracing it or changing it is right for you.

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