Heterochromia is a variation in
color
Color (American English) or colour (British English) is the visual perceptual property deriving from the spectrum of light interacting with the photoreceptor cells of the eyes. Color categories and physical specifications of color are associ ...
ation. The term is most often used to describe color differences of the
iris
Iris most often refers to:
*Iris (anatomy), part of the eye
*Iris (mythology), a Greek goddess
* ''Iris'' (plant), a genus of flowering plants
* Iris (color), an ambiguous color term
Iris or IRIS may also refer to:
Arts and media
Fictional ent ...
, but can also be applied to color variation of
hair
Hair is a protein filament that grows from follicles found in the dermis. Hair is one of the defining characteristics of mammals.
The human body, apart from areas of glabrous skin, is covered in follicles which produce thick terminal and f ...
or
skin
Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation.
Other cuticle, animal coverings, such as the arthropod exoskeleton, have diffe ...
. Heterochromia is determined by the production, delivery, and concentration of
melanin
Melanin (; from el, μέλας, melas, black, dark) is a broad term for a group of natural pigments found in most organisms. Eumelanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amino ...
(a
pigment
A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic compo ...
). It may be
inherited, or caused by genetic
mosaicism
Mosaicism or genetic mosaicism is a condition in multicellular organisms in which a single organism possesses more than one genetic line as the result of genetic mutation. This means that various genetic lines resulted from a single fertilized ...
,
chimerism
A genetic chimerism or chimera ( ) is a single organism composed of cells with more than one distinct genotype. In animals, this means an individual derived from two or more zygotes, which can include possessing blood cells of different blood ...
,
disease
A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...
, or
injury
An injury is any physiological damage to living tissue caused by immediate physical stress. An injury can occur intentionally or unintentionally and may be caused by blunt trauma, penetrating trauma, burning, toxic exposure, asphyxiation, o ...
.
It occurs in humans and certain breeds of domesticated animals.
Heterochromia of the
eye is called heterochromia iridum or heterochromia iridis. It can be complete or sectoral. In complete heterochromia, one iris is a different color from the other. In sectoral heterochromia, part of one iris is a different color from its remainder. In central heterochromia, there is a ring around the pupil or possibly spikes of different colors radiating from the pupil.
Though multiple causes have been posited, the scientific consensus is that a lack of
genetic diversity is the primary reason behind heterochromia, at least in domestic animals. This is due to a mutation of the genes that determine melanin distribution at the 8-HTP pathway, which usually only become corrupted due to chromosomal homogeneity.
Though common in some breeds of cats, dogs, cattle and horses due to inbreeding, heterochromia is uncommon in humans, affecting fewer than 200,000 people in the United States, and is not associated with lack of genetic diversity.
The affected eye may be hyperpigmented (hyperchromic) or hypopigmented (hypochromic).
In humans, an increase of melanin production in the eyes indicates
hyperplasia of the iris tissues, whereas a lack of melanin indicates
hypoplasia.
The term is derived from
Ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...
: , "different" and , "color".
Background
Eye color
Eye color is a polygenic phenotypic character determined by two distinct factors: the pigmentation of the eye's iris and the frequency-dependence of the scattering of light by the turbid medium in the stroma of the iris.
In humans, the pi ...
, specifically the color of the irises, is determined primarily by the concentration and distribution of melanin. Although the processes determining eye color are not fully understood, it is known that inherited eye color is determined by multiple
genes
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
. Environmental or acquired factors can alter these inherited traits.
The color of the mammalian, including human, iris is very variable. However, there are only two pigments present,
eumelanin
Melanin (; from el, μέλας, melas, black, dark) is a broad term for a group of natural pigments found in most organisms. Eumelanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amin ...
and
pheomelanin
Melanin (; from el, μέλας, melas, black, dark) is a broad term for a group of natural pigments found in most organisms. Eumelanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the a ...
. The overall concentration of these pigments, the ratio between them, variation in the distribution of pigment in the layers of the stroma of the iris and the effects of light scattering all play a part in determining eye color.
Classification
![Autosomal Dominant Pedigree Chart](https://upload.wikimedia.org/wikipedia/commons/6/63/Autosomal_Dominant_Pedigree_Chart.svg)
Heterochromia is classified primarily by onset: as either
genetic or acquired. Although a distinction is frequently made between heterochromia that affects an eye completely or only partially (sectoral heterochromia), it is often classified as either genetic (due to
mosaicism
Mosaicism or genetic mosaicism is a condition in multicellular organisms in which a single organism possesses more than one genetic line as the result of genetic mutation. This means that various genetic lines resulted from a single fertilized ...
or
congenital
A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can ...
) or acquired, with mention as to whether the affected iris or portion of the iris is darker or lighter.
[Swann P]
"Heterochromia."
''Optometry Today.'' January 29, 1999. Retrieved November 1, 2006. Most cases of heterochromia are hereditary, or caused by genetic factors such as chimerism, and are entirely benign and unconnected to any pathology, however, some are associated with certain diseases and syndromes. Sometimes one eye may change color following disease or injury.
Genetic
Abnormal iris darker
*
Lisch nodules
Lisch nodule, also known as iris hamartoma, is a pigmented hamartomatous nodular aggregate of dendritic melanocytes affecting the iris, named after Austrian ophthalmologist Karl Lisch (1907–1999), who first recognized them in 1937.
The first ...
– iris
hamartoma
A hamartoma is a mostly benign, local malformation of cells that resembles a neoplasm of local tissue but is usually due to an overgrowth of multiple aberrant cells, with a basis in a systemic genetic condition, rather than a growth descended fr ...
s seen in
neurofibromatosis
Neurofibromatosis (NF) is a group of three conditions in which tumors grow in the nervous system. The three types are neurofibromatosis type I (NF1), neurofibromatosis type II
Neurofibromatosis type II (also known as MISME syndrome – multi ...
.
*
Ocular melanosis
Ocular melanosis (OM) is a blue-gray and/or brown lesion of the conjunctiva that can be separated into benign conjunctival epithelial melanosis (BCEM) and primary acquired melanosis (PAM), of which the latter is considered a risk factor for uveal m ...
– a condition characterized by increased pigmentation of the
uveal tract
The uvea (; Lat. ''uva'', "grape"), also called the ''uveal layer'', ''uveal coat'', ''uveal tract'', ''vascular tunic'' or ''vascular layer'' is the pigmented middle of the three concentric layers that make up an eye.
History and etymolog ...
,
episclera
The episclera is the outermost layer of the sclera (the white of the eye).Cassin, B. and Solomon, S. ''Dictionary of Eye Terminology''. Gainesville, Florida: Triad Publishing Company, 1990. It is composed of loose, fibrous, elastic tissue and atta ...
, and anterior chamber angle.
*
Oculodermal melanocytosis (nevus of Ota)
*
Pigment dispersion syndrome
Pigment dispersion syndrome (PDS) is an eye disorder that can lead to a form of glaucoma known as pigmentary glaucoma. It takes place when pigment cells slough off from the back of the iris and float around in the aqueous humor. Over time, these ...
– a condition characterized by loss of pigmentation from the posterior iris surface which is disseminated intraocularly and deposited on various intraocular structures, including the anterior surface of the iris.
*
Sturge–Weber syndrome
Sturge–Weber syndrome, sometimes referred to as encephalotrigeminal angiomatosis, is a rare congenital neurological and skin disorder. It is one of the phakomatoses and is often associated with port-wine stains of the face, glaucoma, seizures, i ...
– a syndrome characterized by a
port-wine stain
A port-wine stain (''nevus flammeus'') is a discoloration of the human skin caused by a vascular anomaly (a capillary malformation in the skin). They are so named for their coloration, which is similar in color to port wine, a fortified red wi ...
nevus in the distribution of the trigeminal nerve,
ipsilateral
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...
leptomeningeal angiomas with intracranial calcification and neurologic signs, and angioma of the choroid, often with
secondary glaucoma Secondary glaucoma is a collection of progressive optic nerve disorders associated with a rise in intraocular pressure (IOP) which results in the loss of vision. In clinical settings, it is defined as the occurrence of IOP above 21 mmHg requiring th ...
.
Abnormal iris lighter
![Heterochromia plos](https://upload.wikimedia.org/wikipedia/commons/a/a8/Heterochromia_plos.png)
*Simple heterochromia – a rare condition characterized by the absence of other ocular or systemic problems. The lighter eye is typically regarded as the affected eye as it usually shows iris
hypoplasia. It may affect an iris completely or only partially.
*
Congenital Horner's syndrome – sometimes inherited, although usually acquired.
*
Waardenburg syndrome
Waardenburg syndrome is a group of rare genetic conditions characterised by at least some degree of congenital hearing loss and pigmentation deficiencies, which can include bright blue eyes (or one blue eye and one brown eye), a white foreloc ...
– a syndrome in which heterochromia is expressed as a bilateral iris hypochromia in some cases. A Japanese review of 11 children with albinism found that the condition was present. All had sectoral/partial heterochromia.
*
Piebaldism
Piebaldism refers to the absence of mature melanin-forming cells (melanocytes) in certain areas of the skin and hair. It is a rare autosomal dominant disorder of melanocyte development.James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews ...
– similar to Waardenburg's syndrome, a rare disorder of melanocyte development characterized by a white forelock and multiple symmetrical hypopigmented or depigmented
macules
A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of this s ...
.
*
Hirschsprung's disease
Hirschsprung's disease (HD or HSCR) is a birth defect in which nerves are missing from parts of the intestine. The most prominent symptom is constipation. Other symptoms may include vomiting, abdominal pain, diarrhea and slow growth. Symptoms us ...
– a bowel disorder associated with heterochromia in the form of a sector hypochromia. The affected sectors have been shown to have reduced numbers of melanocytes and decreased stromal pigmentation.
*
Incontinentia pigmenti
Incontinentia pigmenti (IP) is a rare X-linked dominant genetic disorder that affects the skin, hair, teeth, nails and central nervous system. It is named from its appearance under a microscope.
The disease is characterized by skin abnormalitie ...
*
Parry–Romberg syndrome
Parry–Romberg syndrome (PRS) is a rare disease characterized by progressive shrinkage and degeneration of the tissues beneath the skin, usually on only one side of the face (hemifacial atrophy) but occasionally extending to other parts of th ...
Acquired
![Sled dog on Svalbard with heterochromia](https://upload.wikimedia.org/wikipedia/commons/6/69/Sled_dog_on_Svalbard_with_heterochromia.jpg)
Acquired heterochromia is usually due to injury, inflammation, the use of certain eyedrops that damage the iris, or tumors.
Abnormal iris darker
*Deposition of material
**
Siderosis
Siderosis is the deposition of excess iron in body tissue. When used without qualification, it usually refers to an environmental disease of the lung, also known more specifically as pulmonary siderosis or Welder's disease, which is a form of pneu ...
– iron deposition within ocular tissues due to a penetrating injury and a retained iron-containing, intraocular foreign body.
**
Hemosiderosis
Hemosiderosis is a form of iron overload disorder resulting in the accumulation of hemosiderin.
Types include:
* Transfusion hemosiderosis
* Idiopathic pulmonary hemosiderosis
* Transfusional diabetes
Organs affected:
* Hemosiderin deposit ...
– long standing hyphema (blood in the anterior chamber) following blunt trauma to the eye may lead to iron deposition from blood products.
*Certain eyedrops –
prostaglandin analogues (
latanoprost
Latanoprost, sold under the brand name Xalatan among others, is a medication used to treat increased pressure inside the eye. This includes ocular hypertension and open angle glaucoma. It is applied as eye drops to the eyes. Onset of effects i ...
, isopropyl unoprostone,
travoprost
Travoprost, sold under the brand name Travatan among others, is a medication used to treat high pressure inside the eye including glaucoma. Specifically it is used for open angle glaucoma when other agents are not sufficient. It is used as an eye ...
, and
bimatoprost
Bimatoprost, sold under the brand name Lumigan among others, is a medication used to treat high pressure inside the eye including glaucoma. Specifically it is used for open angle glaucoma when other agents are not sufficient. It may also be used ...
) are used topically to lower
intraocular pressure
Intraocular pressure (IOP) is the fluid pressure inside the eye. Tonometry is the method eye care professionals use to determine this. IOP is an important aspect in the evaluation of patients at risk of glaucoma. Most tonometers are calibrated t ...
in
glaucoma
Glaucoma is a group of eye diseases that result in damage to the optic nerve (or retina) and cause vision loss. The most common type is open-angle (wide angle, chronic simple) glaucoma, in which the drainage angle for fluid within the eye rem ...
patients. A concentric heterochromia has developed in some patients applying these drugs. A stimulation of melanin synthesis within iris melanocytes has been postulated.
*
Neoplasm
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
– Nevi and melanomatous tumors.
*Iridocorneal endothelium syndrome
*Iris ectropion syndrome
Abnormal iris lighter
*
Fuchs heterochromic iridocyclitis
Fuchs heterochromic iridocyclitis (FHI) is a chronic unilateral uveitis appearing with the triad of heterochromia, predisposition to cataract and glaucoma, and keratitic precipitates on the posterior corneal surface. Patients are often asymptomati ...
– a condition characterized by a low grade, asymptomatic
uveitis
Uveitis () is inflammation of the uvea, the pigmented layer of the eye between the inner retina and the outer fibrous layer composed of the sclera and cornea. The uvea consists of the middle layer of pigmented vascular structures of the eye and in ...
in which the iris in the affected eye becomes hypochromic and has a washed-out, somewhat moth eaten appearance. The heterochromia can be very subtle, especially in patients with lighter colored irides. It is often most easily seen in daylight. The prevalence of heterochromia associated with Fuchs has been estimated in various studies
with results suggesting that there is more difficulty recognizing iris color changes in dark-eyed individuals.
*
Acquired Horner's syndrome – usually acquired, as in
neuroblastoma
Neuroblastoma (NB) is a type of cancer that forms in certain types of nerve tissue. It most frequently starts from one of the adrenal glands but can also develop in the neck, chest, abdomen, or spine. Symptoms may include bone pain, a lump in th ...
, although sometimes inherited.
*
Neoplasm
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
–
Melanoma
Melanoma, also redundantly known as malignant melanoma, is a type of skin cancer that develops from the pigment-producing cells known as melanocytes. Melanomas typically occur in the skin, but may rarely occur in the mouth, intestines, or eye ( ...
s can also be very lightly pigmented, and a lighter colored iris may be a rare manifestation of metastatic disease to the eye.
*
Parry–Romberg syndrome
Parry–Romberg syndrome (PRS) is a rare disease characterized by progressive shrinkage and degeneration of the tissues beneath the skin, usually on only one side of the face (hemifacial atrophy) but occasionally extending to other parts of th ...
– due to tissue loss.
Heterochromia has also been observed in those with
Duane syndrome
Duane syndrome is a congenital rare type of strabismus most commonly characterized by the inability of the eye to move outward. The syndrome was first described by ophthalmologists Jakob Stilling (1887) and Siegmund Türk (1896), and subsequentl ...
.
*Chronic
iritis
Uveitis () is inflammation of the uvea, the pigmented layer of the eye between the inner retina and the outer fibrous layer composed of the sclera and cornea. The uvea consists of the middle layer of pigmented vascular structures of the eye and i ...
*Juvenile
xanthogranuloma
*
Leukemia
Leukemia ( also spelled leukaemia and pronounced ) is a group of blood cancers that usually begin in the bone marrow and result in high numbers of abnormal blood cells. These blood cells are not fully developed and are called ''blasts'' or ' ...
and
lymphoma
Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). In current usage the name usually refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enlar ...
Partial heterochromia – different colors in the same iris
Partial heterochromia is most often a benign trait of genetic origins, but, like complete heterochromia, can be acquired or be related to clinical syndromes.
Sectoral
In sectoral heterochromia, areas of the same iris contain two different colors, the contrasting colors being demarcated in a radial, or sectoral, manner. Sectoral heterochromia may affect one or both eyes.
It is unknown how rare sectoral heterochromia is in humans, but it is considered to be less common than complete heterochromia.
Central
![Pronounced Central Heterochromia - Human Eye](https://upload.wikimedia.org/wikipedia/commons/f/f1/Pronounced_Central_Heterochromia_-_Human_Eye.jpg)
Central heterochromia is also an eye condition where there are two colors in the same iris; but the arrangement is concentric, rather than sectoral. The central (pupillary) zone of the iris is a different color than the mid-peripheral (ciliary) zone. Central heterochromia is more noticeable in irises containing low amounts of
melanin
Melanin (; from el, μέλας, melas, black, dark) is a broad term for a group of natural pigments found in most organisms. Eumelanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amino ...
.
In history and culture
Heterochromia of the eye was first described as a human condition by
Aristotle
Aristotle (; grc-gre, Ἀριστοτέλης ''Aristotélēs'', ; 384–322 BC) was a Greek philosopher and polymath during the Classical period in Ancient Greece. Taught by Plato, he was the founder of the Peripatetic school of phil ...
, who termed it ''heteroglaucos''.
Notable historical figures thought to have heterochromia include the
Byzantine emperor
This is a list of the Byzantine emperors from the foundation of Constantinople in 330 AD, which marks the conventional start of the Eastern Roman Empire, to its fall to the Ottoman Empire in 1453 AD. Only the emperors who were recognized as le ...
Anastasius the First, dubbed ''dikoros'' (Greek for 'having two pupils'). "His right eye was light blue, while the left was black, nevertheless his eyes were most attractive", is the description of the historian
John Malalas
John Malalas ( el, , ''Iōánnēs Malálas''; – 578) was a Byzantine chronicler from Antioch (now Antakya, Turkey).
Life
Malalas was of Syrian descent, and he was a native speaker of Syriac who learned how to write in Greek later in ...
. A more recent example is the German poet, playwright, novelist, scientist, statesman, theatre director, and critic,
Johann Wolfgang Goethe
Johann Wolfgang von Goethe (28 August 1749 – 22 March 1832) was a German poet, playwright, novelist, scientist, statesman, theatre director, and critic. His works include plays, poetry, literature, and aesthetic criticism, as well as treatis ...
.
The ''
Alexander Romance'', an early literary treatment of the life of
Alexander the Great
Alexander III of Macedon ( grc, wikt:Ἀλέξανδρος, Ἀλέξανδρος, Alexandros; 20/21 July 356 BC – 10/11 June 323 BC), commonly known as Alexander the Great, was a king of the Ancient Greece, ancient Greek kingdom of Maced ...
, attributes heterochromia to him. In it he is described as having one eye light and one eye dark. However, no ancient historical source mentions this. It is used to emphasise the otherworldly and heroic qualities of Alexander.
In the
Ars Amatoria
The ''Ars amatoria'' ( en, The Art of Love) is an instructional elegy series in three books by the ancient Roman poet Ovid. It was written in 2 AD.
Background
Book one of ''Ars amatoria'' was written to show a man how to find a woman. In book two ...
, the Roman poet
Ovid
Pūblius Ovidius Nāsō (; 20 March 43 BC – 17/18 AD), known in English as Ovid ( ), was a Roman poet who lived during the reign of Augustus. He was a contemporary of the older Virgil and Horace, with whom he is often ranked as one of the th ...
describes the witch Dipsas as having 'double pupils'. Kirby Flower Smith suggested that this could be understood as heterochromia, though other scholars have disagreed. The Roman jurist and writer
Cicero
Marcus Tullius Cicero ( ; ; 3 January 106 BC – 7 December 43 BC) was a Roman statesman, lawyer, scholar, philosopher, and academic skeptic, who tried to uphold optimate principles during the political crises that led to the estab ...
also mentions the same feature of 'double pupils' as being found in some
Italic women.
Pliny the Elder
Gaius Plinius Secundus (AD 23/2479), called Pliny the Elder (), was a Roman author, naturalist and natural philosopher, and naval and army commander of the early Roman Empire, and a friend of the emperor Vespasian. He wrote the encyclopedic '' ...
related this feature to the concept of 'the
evil eye
The Evil Eye ( grc, ὀφθαλμὸς βάσκανος; grc-koi, ὀφθαλμὸς πονηρός; el, (κακό) μάτι; he, עַיִן הָרָע, ; Romanian: ''Deochi''; it, malocchio; es, mal de ojo; pt, mau-olhado, olho gordo; ar ...
'.
The twelfth-century scholar
Eustathius, in his commentary on the Iliad, reports a tradition in which the
Thracian
The Thracians (; grc, Θρᾷκες ''Thrāikes''; la, Thraci) were an Indo-European speaking people who inhabited large parts of Eastern and Southeastern Europe in ancient history.. "The Thracians were an Indo-European people who occupied t ...
Thamyris
In Greek mythology, Thamyris (Ancient Greek: Θάμυρις, ''Thámuris'') was a Thracian singer. He is notable in Greek mythology for reportedly being a lover of Hyacinth and thus to have been the first male to have loved another male, but when ...
(son of the nymph
Argiope), who was famed for his musical abilities, had one eye that was grey, whilst the other was black. W. B. McDaniel suggests that this should be interpreted as heterochromia.
In other animals
Although infrequently seen in humans, complete heterochromia is more frequently observed in species of domesticated mammals. The blue eye occurs within a white spot, where melanin is absent from the skin and hair (see
Leucism
Leucism () is a wide variety of conditions that result in the partial loss of pigmentation in an animal—causing white, pale, or patchy coloration of the skin, hair, feathers, scales, or cuticles, but not the eyes. It is occasionally spelled ' ...
). These species include the
cat
The cat (''Felis catus'') is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members of ...
, particularly breeds such as
Turkish Van
The Turkish Van (pronounced Von) is a naturally occurring breed of domestic cat that originated in the Lake Van area of modern-day Turkey, part of Armenian Highlands. The Van is classified as a semi-long hair, but it has two lengths of hair, de ...
,
Turkish Angora
The Turkish Angora ( tr, Ankara kedisi, "Ankara cat") is a breed of domestic cat. Turkish Angoras are one of the ancient, natural breeds of cat, having originated in central Anatolia (modern-day Turkey, Ankara region). The breed has been document ...
,
Khao Manee
The Khao Manee cat ( th, ขาวมณี, , lit. "white jewel"), or Khao Plort ( th, ขาวปลอด, lit. "complete white"), also known as the Diamond Eye cat, is a rare breed of cat originating in Thailand, which has an ancient ancest ...
and (rarely)
Japanese Bobtail
The Japanese Bobtail is a breed of domestic cat with an unusual bobtail more closely resembling the tail of a rabbit than that of other cats. The variety is native to Japan, though it is now found throughout the world. The breed has been know ...
. These so-called
odd-eyed cat
An odd-eyed cat is a cat with one blue eye and one eye either green, yellow, or brown. This is a feline form of complete heterochromia,Foster, Race and Smith, Marty, ( DVMs)Heterochromia, A-Z Health Library, Purina-One. Retrieved February 2007 ...
s are white, or mostly white, with one normal eye (copper, orange, yellow, green), and one blue eye. Among
dog
The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the wolf. Also called the domestic dog, it is derived from the extinct Pleistocene wolf, and the modern wolf is the dog's nearest living relative. Do ...
s, complete heterochromia is seen often in the
Siberian Husky and few other breeds, usually
Australian Shepherd
The Australian Shepherd is a breed of herding dog from the United States. The name of the breed is technically a misnomer, as it was developed in California in the 19th century; the breed was unknown in Australia at the time. It is claimed that A ...
and
Catahoula Leopard Dog
The Catahoula Leopard Dog is an American dog breed named after Catahoula Parish, Louisiana. It became the state dog of Louisiana in 1979. It is recognized by the United Kennel Club under the name ''Louisiana Catahoula Leopard Dog'', while the Ame ...
and rarely in
Shih Tzu
The Shih Tzu (, ; literally " Hsi Shih dog") is a toy dog breed originating from Tibet and was bred from the Pekingese and the Lhasa Apso.
Shih Tzus are known for their short snouts and large round eyes, as well as their long coat, floppy ear ...
. Horses with complete heterochromia have one brown and one white, gray, or blue eye—complete heterochromia is more common in horses with
pinto
Pinto is a Portuguese language, Portuguese, Spanish language, Spanish, Sephardi Jews, Jewish (Sephardic), and Italian language, Italian surname. It is a high-frequency surname in all List of countries and territories where Portuguese is an officia ...
coloring. Complete heterochromia occurs also in
cattle
Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus ''Bos''. Adult females are referred to as cows and adult mal ...
and even
water buffalo
The water buffalo (''Bubalus bubalis''), also called the domestic water buffalo or Asian water buffalo, is a large bovid originating in the Indian subcontinent and Southeast Asia. Today, it is also found in Europe, Australia, North America, So ...
. It can also be seen in ferrets with
Waardenburg syndrome
Waardenburg syndrome is a group of rare genetic conditions characterised by at least some degree of congenital hearing loss and pigmentation deficiencies, which can include bright blue eyes (or one blue eye and one brown eye), a white foreloc ...
, although it can be very hard to tell at times as the eye color is often a midnight blue.
Sectoral heterochromia, usually sectoral hypochromia, is often seen in
dog
The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the wolf. Also called the domestic dog, it is derived from the extinct Pleistocene wolf, and the modern wolf is the dog's nearest living relative. Do ...
s, specifically in breeds with
merle
Merle may refer to:
People
*Merle (given name), a given name used by both men and women
*Merle (surname), a surname of French origin
Others
*Merle (dog coat), a pattern in dogs’ coats
*Merle (grape), another name for the wine grape Merlot
*Akaf ...
coats. These breeds include the
Australian Shepherd
The Australian Shepherd is a breed of herding dog from the United States. The name of the breed is technically a misnomer, as it was developed in California in the 19th century; the breed was unknown in Australia at the time. It is claimed that A ...
,
Border Collie
The Border Collie is a Scottish breed of herding dog of medium size. Widely considered to be the most intelligent dog breed, they are descended from landrace sheepdogs once found all over the British Isles, but became standardised in the Angl ...
,
Collie
Collies form a distinctive type of herding dogs, including many related landraces and standardized breeds. The type originated in Scotland and Northern England. Collies are medium-sized, fairly lightly-built dogs, with pointed snouts. Many ...
,
Shetland Sheepdog
The Shetland Sheepdog, often known as the Sheltie, is a breed of herding dog that originated in the Shetland Islands of Scotland. The original name was ''Shetland Collie,'' but this caused controversy amongst Rough Collie breeders of the time, s ...
,
Welsh Corgi
The Welsh Corgi ( or Corgi, plural Corgis, or occasionally the etymologically consistent Corgwn; ) is a small type of herding dog that originated in Wales. The name ''corgi'' is derived from the Welsh words and (which is mutated to ), mea ...
,
Pyrenean Shepherd
The Pyrenean Sheepdog, the Chien de Berger des Pyrénées in French, is a small to medium-sized breed of herding dog from the Pyrenees Mountains region of France. It is found herding flocks of sheep throughout the Pyrenees alongside the much larger ...
,
Mudi
The Mudi is a herding dog breed from Hungary. It is closely related to the Puli and Pumi, from which it was separated in the 1930s. They continue to be used in herding, as well as participating in a variety of dog sports.
History
The ...
,
Beauceron
The Beauceron is a herding dog breed originating from the plains of Central France. The Beauceron is also known as Berger de Beauce (sheepdog from Beauce) or Bas Rouge (red-stockings).
History
A French herding breed known for centuries in west ...
,
Catahoula Cur
The Catahoula Leopard Dog is an American dog breed named after Catahoula Parish, Louisiana. It became the state dog of Louisiana in 1979. It is recognized by the United Kennel Club under the name ''Louisiana Catahoula Leopard Dog'', while the Ame ...
,
Dunker
A Dunker, also known as the Norwegian Hound, is a medium-sized breed of dog from Norway. It was bred by Wilhelm Dunker to be a scenthound by crossing a Russian Harlequin Hound with dependable Norwegian scent hounds.
It is a very rare dog b ...
,
Great Dane
The Great Dane is a large sized dog breed originating from Germany. The Great Dane descends from hunting dogs from the Middle Ages used to hunt wild boar and deer, and as guardians of German nobility. It is one of the largest breeds in the world ...
,
Dachshund
The dachshund ( or ; German: "badger dog"), also known as the wiener dog, badger dog, and sausage dog, is a short-legged, long-bodied, hound-type dog breed. The dog may be smooth-haired, wire-haired, or long-haired, and comes in a variety of c ...
and
Chihuahua. It also occurs in certain breeds that do not carry the merle trait, such as the
Siberian Husky and rarely,
Shih Tzu
The Shih Tzu (, ; literally " Hsi Shih dog") is a toy dog breed originating from Tibet and was bred from the Pekingese and the Lhasa Apso.
Shih Tzus are known for their short snouts and large round eyes, as well as their long coat, floppy ear ...
. There are examples of cat breeds that have the condition such as
Van cat
The Van cat ( tr, Van kedisi; ; Eastern ; ku, pisîka Wanê, script=Latn, italic=yes) is a distinctive landrace of the domestic cat found in the Lake Van area of the Armenian Highlands in Turkey.
Van cats are relatively large, have a chal ...
.
[ ]
Gallery
File:Heterochromia Iridis.jpg, Complete heterochromia in a child.
File:Sectoral Heterochromia5600.jpg, A young adult human exhibiting sectoral heterochromia in the form of an orange-brown segment in blue eye.
File:Heterochromia Blue Orange.png, Human eye with central heterochromia showing an orange-brown to blue iris.
File:Alice Eve, Men in Black 3, 2012 (crop).jpg, Actress Alice Eve
Alice Sophia Eve (born ) is a British actress. Her movie career includes roles in ''She's Out of My League'', ''Men in Black 3'', ''Star Trek Into Darkness'', and '' Before We Go''. She has had recurring roles on the TV series ''Entourage'' and ...
has heterochromia: her left eye is blue and right eye is green.
File:Shane Warne February 2015.jpg, Australian cricketer Shane Warne
Shane Keith Warne (13 September 1969 – 4 March 2022) was an Australian international cricketer, whose career ran from 1991 to 2007. Warne played as a right-arm leg spin bowler and a right-handed batsman for Victoria, Hampshire and Australia ...
had complete heterochromia: his left eye was green and right eye was blue.
File:Anouchka Delon 2014.jpg, Actress Anouchka Delon
Anouchka Delon (born 25 November 1990) is a French-Dutch actress.
Early life
Delon is the daughter of Alain Delon and Rosalie van Breemen. She has a younger brother, Alain-Fabien Delon, and two older half-brothers, Christian Aaron "Ari" Bo ...
: brown and blue
File:Nationals pitcher Max Scherzer talks to reporters at 2016 All-Star Game availability. (28232354950).jpg, Professional baseball
Baseball is a bat-and-ball sport played between two teams of nine players each, taking turns batting and fielding. The game occurs over the course of several plays, with each play generally beginning when a player on the fielding tea ...
pitcher Max Scherzer
Maxwell Martin Scherzer (born July 27, 1984) is an American professional baseball pitcher for the New York Mets of Major League Baseball (MLB). He previously played in MLB for the Arizona Diamondbacks, Detroit Tigers, Washington Nationals, and L ...
has complete heterochromia: his right eye is blue and his left eye is brown.
File:Kate Bosworth Deauville 2011.jpg, Actress Kate Bosworth
Catherine Anne Bosworth (born January 2, 1983) is an American actress. Following minor roles in the films '' The Horse Whisperer'' (1998) and ''Remember the Titans'' (2000), she rose to prominence with her role as a young surfer in the box-offi ...
has complete heterochromia: her left eye is blue and her right eye is hazel.
File:Dominic Sherwood (22429006997).jpg, Actor Dominic Sherwood has sectoral heterochromia.
File:Henry Cavill-2665842.jpg, Actor Henry Cavill
Henry William Dalgliesh Cavill ( ; born 5 May 1983) is a British actor. He is known for his portrayal of Charles Brandon in Showtime's ''The Tudors'' (2007–2010), DC Comics character Superman in the DC Extended Universe (2013–2022), Gera ...
has sectoral heterochromia.
File:Heterochromia sled dog.jpg, Complete heterochromia in a female sled dog
File:Husky pysk 89.jpg, Complete heterochromia in a Siberian Husky: one eye blue, one eye brown.
File:DogEye2color cr wb.jpg, Sectoral hypochromia in a blue merle Border Collie
The Border Collie is a Scottish breed of herding dog of medium size. Widely considered to be the most intelligent dog breed, they are descended from landrace sheepdogs once found all over the British Isles, but became standardised in the Angl ...
.
File:Heterochromia in a mutt dog.jpg, Sectoral heterochromia in a mutt dog.
File:Angoraturco.jpg, A Turkish Angora
The Turkish Angora ( tr, Ankara kedisi, "Ankara cat") is a breed of domestic cat. Turkish Angoras are one of the ancient, natural breeds of cat, having originated in central Anatolia (modern-day Turkey, Ankara region). The breed has been document ...
cat with complete heterochromia.
File:Central heterochromia cat.jpg, Central heterochromia in a bicolor tabby cat.
Misattribution
English singer
David Bowie
David Robert Jones (8 January 194710 January 2016), known professionally as David Bowie ( ), was an English singer-songwriter and actor. A leading figure in the music industry, he is regarded as one of the most influential musicians of the ...
exhibited
anisocoria
Anisocoria is a condition characterized by an unequal size of the eyes' pupils. Affecting up to 20% of the population, anisocoria is often entirely harmless, but can be a sign of more serious medical problems.
Causes
Anisocoria is a common condit ...
(one pupil was larger than the other), owing to a teenage injury.
This was sometimes mistaken for heterochromia iridum.
See also
References
External links
''Photograph of Radial Reddish Sunburst Pattern in Right Eye of Bluish Hazel Eyed Woman''
{{Medicine
Disturbances of pigmentation
Eye color
Eye diseases
Genodermatoses
Medical signs