Heterochromia Iridum—People With Two Different Colored Eyes

Updated on June 17, 2017

The terms “Heterochromia iridum” and “Heterochromia iridis” are often used interchangeably to refer to a condition characterized by two different colored eyes. But often again, both terms are distinguished by nitpickers.

Heterochromia iridis is when one or more regions of the same iris are pigmented differently from the rest of the iris. The iris is a circular structure inside your eyeball that displays your eye color.

Heterochromia iridum is when both eyes have different colors [1]; it is for people with two different colored eyes.

How About a Bit of Greek?

The word “Heterochromia” literally means “difference in color or pigmentation.” The word is also used to refer to a pigmentation difference in the skin and hair. Heterochromia in the skin and hair are less common than that of the eye. For simplicity, heterochromia of the eyes will simply be referred to hereafter as heterochromia.

Heteros = different

Chromia = color or pigmentation

Iridis = pertains to one iris / Iridum = pertains to both irises

Types of Heterochromia

There are three main types namely;

  • Complete heterochromia
  • Central heterochromia
  • Sectoral heterochromia

Complete Heterochromia

This is the type of heterochromia where one eye has a different color from the other. It is also referred to as Heterochromia iridum. Complete heterochromia reminds me of Amy, a character in the movie X-men First Class. Professor X described her eye condition as a very “groovy” mutation.

Alice Eve is a famous actress with complete heterochromia. Her right eye is green, and her left eye is blue. She is best known for her featured roles in several movies including the 2013 Star Trek into Darkness.

Alice Eve has complete heterochromia
Alice Eve has complete heterochromia | Source

Alice Eve Talks About Her Eyes

Cats Have It Too

Source

Central Heterochromia

Does Angelina Jolie have central heterochromia? Maybe that is what gives her such a penetrating gaze. This type of heterochromia is characterized by a ring around the pupil with a different pigmentation from the rest of the iris. The ring is usually located at the centre of the iris closest to the pupil.

It is sometimes very easy to confuse central heterochromia with the hazel eye color. There is a huge variety of hazel eyes, they generally show a continuous shift in color from brown to green as you move outwards from the pupil. The boundary between two colors is more distinct in heterochromia.

Sectoral Heterochromia

Sectoral heterochromia, also known as Partial heterochromia, is the type where one portion (or more portions) of the iris has a different color from the rest of the iris.

Sectoral heterochromia
Sectoral heterochromia | Source

Another famous person with heterochromia is Elizabeth Berkley. She was born with Sectoral heterochromia in her right eye; there is a brown section in the lower part of her right iris.

Elizabeth Berkley & Greg Lauren
Elizabeth Berkley & Greg Lauren | Source

Causes of Heterochromia

Heterochromia of the eye happens because of a disturbance in the distribution of pigment in the iris. Either one eye has more pigment than the other or portions of the same iris are pigmented differently from the rest of the iris.

Pigments are like ingredients for eye color while the concentration of each pigment is like the recipe.

— the Author

Most cases of heterochromia are benign. They are often not accompanied by visual complaints or health abnormalities. The causes of heterochromia of the eye can be classified either as genetic or acquired. When it is acquired, it can be from a disease or from an injury.

  • Congenital heterochromia (Genetic)
  • Acquired heterochromia
    • Injury
    • Disease
    • Medication

Congenital Heterochromia

Most people with heterochromia inherited it from a parent, this is called congenital heterochromia. The gene for heterochromia is autosomal dominant. This means that if a parent has it, there is a good chance it will be passed down through generations.

Some congenital heterochromia is due to syndromes such as Waardenburg syndrome. These are genetic disorders that disrupt the even distribution of pigment which then affects eye color.

Scientists are only beginning to scratch the surface of how eye color is inherited. There are times when Mother Nature mixes things up in weird and wonderful ways. Central and Sectoral heterochromia can either affect one or both eyes. It is also possible for one person to express more than one type of heterochromia.

I once met a girl who has both central and complete heterochromia. Her right eye is green and her left eye is blue. Surrounding the pupil of her green eye is a copper colored ring.

Acquired Heterochromia

This type can be obtained from injury, disease or as a side-effect of certain medications.

Injuries that cause bleeding inside the eyeball may lead to heterochromia. When blood leaks into the eyeball, depending on the severity, it can cause an abnormal deposition and accumulation of iron. An accumulation of iron in the eyeball turns the eye rusty, a condition known as Iron Siderosis. Siderosis can change your green eye into a rusty green eye.

Melanin is a brown pigment that plays a key role in displaying eye color. Medications that disturb the even distribution of melanin in the iris will affect eye color. An eye drop called Levobunolol was found to cause depigmentation in the iris [2]. Researchers also found evidence that another eye drop called Xalatan gradually darkens the irises of some patients. Experts believe that Xalatan triggers the synthesis of melanin. As you may already know, the more melanin you have in your eyes, the darker your eye color.

Poll 1

Do you have heterochromia?

See results

How Rare Is Heterochromia in Humans?

Not much research has been done to come up with a good estimate of the prevalence and incidence of heterochromia.

In one study published in 1966, 7000 Maryland school children were examined for the incidence of heterochromia. About 0.7% of the children examined had segmental heterochromia. No incident of complete heterochromia was reported [3].

Another study performed in 1979 with a larger sample of over 25000 people from Vienna reported different types of heterochromia. In this study, about 0.3% of the people examined had the condition. It was also found that females were two times more likely to have heterochromia than males [4].

The result of such studies should be interpreted with care because the sample was restricted only to specific geographical locations. Hence the results maybe different in other geographical locations or when we consider the world as a whole.

Poll 2

Experts believe that heterochromia is a rare disease. But not much research has been done to estimate which type is the rarest. So which do you think is the rarest type of heterochromia?

See results

Heterochromia in Dogs and Cats

Heterochromia is believed to be more common in animals than in humans.

Sebastian has Complete heterochromia (Iridum)
Sebastian has Complete heterochromia (Iridum) | Source

Some breeds of domestic cats such as the Angora cats are well known for their high incidence of complete heterochromia. They are called Turkish Angora Cats because it is believed that they originated from central Turkey.

The shimmery white coat and the large mismatched almond-shaped eyes give Sebastian quite a fascinating mug.

A husky with Complete heterochromia (Iridum)
A husky with Complete heterochromia (Iridum) | Source

Huskies are famous for their good looks. Maybe it’s their striking masks and piercing eyes that makes them so appealing. Every now and then you’ll find one with two different colored eyes. Huskies are among dog breeds that are more susceptible to express heterochromia.

Let’s round off with Boutros whose blue and brown eyes sort of match the color of its coat.

That being said, you shouldn't take eye color alone as your major consideration should you decide to get a pet. There are definitely other wonderful traits you should also consider.

Comments

    0 of 8192 characters used
    Post Comment

    • AliciaC profile image

      Linda Crampton 

      3 years ago from British Columbia, Canada

      Thank you for sharing this very interesting information. Your hub is both educational and enjoyable.

    working

    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, owlcation.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://owlcation.com/privacy-policy#gdpr

    Show Details
    Necessary
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
    Features
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Marketing
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Statistics
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)