The pupil is a part of your eye that allows the proper quantity of light to reach the retina. It helps you see things clearly by optimizing glare day and night.
But, there is a rare eye condition called Polycoria, in which a person has two or more pupils in one eye.
Most people think this condition is impossible. They ask questions like how do their eyes work? How can they see with polycoria eyes? Does their vision get affected or by how much?
If you also have these questions in your mind, we will help you find answers to each one of them as we will discuss polycoria from start to the end.
Is Polycoria Real or Myth?
Yes, it exists.
Polycoria is an eye disorder that includes the presence of two pupils in one eye. It can impact one eye or both. The condition is present in childhood. But it may be diagnosed later in life. There are two kinds of polycoria:
- True Polycoria
A person with true polycoria has two or more two pupils in one eye. Each pupil owns an intact sphincter muscle that will become small and dilate.
True polycoria is a very uncommon condition. It can affect the response process of the retina to bright lights.
- False Polycoria Or Pseudopolycoria
False polycoria is less rare in comparison to true polycoria. In pseudopolycoria, you may have passive constriction. Passive constriction differentiates the extra pupil from the original pupil during the dilation and constriction process.
The extra pupil in pseudopolycoria is different from the additional pupil of true polycoria. That is because it reflects defects independent of the sphincter muscles.
Pseudopolycoria also links to some uncommon eye conditions, which may include the following:
How Rare Is Polycoria?
Several people consider polycoria a myth. Other eye disorder conditions are commonly mistaken for it. There are not many cases suspected in the history of this disorder.
According to an article published in 2002, till now, only 2 cases of true polycoria have been observed since 1966.
So now you have understood what polycoria is and how rare it is. Let’s move further to know how this condition occurs in detail.
What Are The Causes Of Polycoria?
The exact reason behind the occurrence of polycoria is not known. However, there are some situations associated with this disease:
- Detached Retina
It is a situation where the retina pulls away from its original position. This condition separates the retina cells from the blood vessels that provide oxygen and nutrition. The longer this disorder goes untreated, the more the risk of having polycoria and even permanent vision loss.
- Polar Cataracts
These are small congenital opacities located in the central part of your eye lens. They are of two types, anterior and posterior polar cataracts.
Anterior polar cataracts are small in severity and do not incur vision loss. Posterior polar cataracts may cause vision impairment and require surgery. In some cases, polar cataracts only cause refractive errors in the eyes that can drive a person to situations like polycoria and amblyopia.
- Glaucoma
The polycoria causes also include glaucoma. It is a condition that involves the development of pressure inside the eye that can affect your optic nerve. Such a situation can lead to polycoria and cause total blindness within years.
Here are some uncommon eye conditions to which polycoria is often linked:
- Axenfeld-Rieger Syndrome
Axenfeld-Rieger syndrome is a hereditary condition that incurs false polycoria in your eyes. It is a situation where extra holes appear in the iris and look like you have multiple pupils.
- Iridocorneal Endothelial Syndrome
Iridocorneal endothelial syndrome is an eye disease that distorts the pupil and polycoria. This syndrome is common in women and people between 20-50 years old.
What Are The Symptoms Of Polycoria?
The polycoria symptoms primarily include a combination of having more than one iris muscle. The iris is the colored muscle part around each pupil. It oversees how much light enters the eye.
In the polycoria eye, your pupils tend to be smaller than regular and separated by different segments of the iris. It can imply less light enters your eye, which reduces your vision. You may also face difficulty focusing because your pupils do not work as desired.
The other signs of polycoria may include the following:
- Blurred vision in the polycoria eyes
- Poor or double vision in the defected eye
- Oblong shaped one or both pupils
- Glare issues
- A gap of iris tissue between the both pupils
How Much Does Polycoria Affect Your Vision?
The polycoria eyes do not have normal eyesight. Their vision gets damaged due to the disease, which affects the iris.
Further, this scenario would involve damage to other parts of the eyes, thus affecting vision to a great extent.
With more than one pupil, multiple offset images develop on your macula. In the least good situations, you might witness the development of faint ghosting images wherever you look. In the worst cases, you would notice Monocular Diplopia. It is a condition where you see multiple depictions of things you look at.
How To Diagnose Polycoria?
To diagnose the development of polycoria, you need to visit an eye doctor for a detailed eye exam.
During your visit, the eye specialist will do a slit-lamp test. It is an eye test in which he uses a microscope and special light to examine the front and back of your eyes. This test allows your doctor to see any abnormalities or deficiencies in eye pupils.
After confirming polycoria, your eye doctor will let you know about treatment procedures.
How Can Polycoria Be Treated?
Some persons dealing with this situation do not need treatment to correct polycoria vision as this situation does not affect eyesight much.
But for those whose eyesight had a severe toll because of the conditions, having surgery is the best possible treatment. However, true polycoria is so uncommon that determining the best treatment procedure is very difficult.
However, the doctor may suggest you opt for a surgical polychoric treatment called Pupilloplasty. During this treatment, the surgeon cuts the abnormally developed iris tissue. This step helps you eliminate the gap created between the two pupils.
Another surgical method used to treat polycoria is a double-armed polypropylene suture. The suture is left on the outside of the sclera with a knot buried in the scleral flap.
This surgical procedure facilitates the posterior fixation of intraocular lens implants, which are extremely useful for good eyesight.
Polycoria In Dogs And Cats
Like humans, animals such as cats and dogs can also be the victims of this rare eye condition. The disease gives them more than one pupillary opening in the eyes.
In a polycoria cat and dog, the disorder occurs as an outcome of an injury or disease that affects the iris.
The other causes may include:
- Normal aging
- Uveitis or inflammation of the uvea portion of the dog’s eyes
- Glaucoma
Diagnosis
The veterinarian will do a detailed ophthalmological exam on your pet. The main goal is to find the presence of more than one pupil in a single iris, each with an ability to make themselves smaller.
Treatment
The condition is not reversible. Its treatment aims to halt the underlying cause that began this disease. Moreover, in some cases, the vision of cats and dogs does not get affected. Although, they become sensitive to light.
The Final Word
It is essential to visit your eye doctor for a detailed eye examination every month. These tests allow you to check your eye health and vision.
Further, if you have an eye condition like polycoria, visiting your doctor is a great way to get a timely diagnosis and cure.
If you avoid going for eye tests and think you will go someday when needed. You have been a traitor to yourself.
Contact your eye specialist right away and plan a meeting today.
Do you find this article helpful? Comment below to ask any questions. Also, do not forget to share it with your friends and let them know about this rare eye condition.

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