Heterochromia is a genetic mutation that causes different colors in the irises of the eyes. There are three main types: central heterochromia, where the center of the iris is a different color than the rest; sectoral heterochromia, where a section of the iris is a different color; and full heterochromia, where each iris is a different color entirely. Heterochromia can also be caused by certain diseases or injuries. While it does not pose any safety or health risks, it results in beautifully unique eye coloring.

1. HETEROCHROMIA
A colorful way to see the world.
By Dwight Anders
ENC 3241

2. What is Heterochromia?
 Heterochromia is when pupil color in the eyes
can vary either between the two irises or in
cases of sectoral and central Heterochromia,
an eye can have one iris with multiple colors.
 It is a most artistically intriguing mutation of the
human DNA strand and has been the focus of
many artistic designs in recent history.

3. Sectoral & Central Heterochromia
VS.
Full Heterochromia
Sectoral & Central
 Central Heterochromia is the most
common form of Heterochromia
where (usually) the center of the
eye will have a different color
then the rest of the surrounding
Iris.
 Sectoral Heterochromia is the
least common; and in this case a
very unique change happens to
the Iris where a section of the iris,
much like a slice of pie, has a
different color.
Full
 Full Heterochromia is much more
common then Sectoral
Heterochromia though less often
seen in comparison to Central
Heterochromia. This strand of
Heterochromia is most obvious in
appearance as one Iris will have a
change of color from the other.

4. Examples of variations in
Heterochromia
This is an example of
Full Heterochromia.
Notice the vivid
difference of color
between the two
eyes.
Sectoral Heterochromia
as can be observed is a
distinct change of color
in the Iris.
Central Heterochromia
is a fading of one color
into another from the
inner to outer edges of
the Iris in one eye.

5. Causes of Heterochromia
 There is a variation of ways Heterochromia can be acquired.
 The most direct way is to acquire it genetically.
 Four diseases that have also been identified as having an association with
Heterochromia are Horner’s Syndrome, Waardenburg Syndrome and
Piebald Syndrome and of course Cancer.
 Horner’s Syndrome has been known to affect the nervous system, which
can be the cause of Sectoral Heterochromia when sympathetic nerves in
the eyes can leave a slight portion of the eye pigment free (resulting in a
blue color.)
 Waardenburg Syndrome affects the epidermal layer with respect to
pigmentation and is not really associated with any specific type of
Heterochromia. Piebald Syndrome is much the same way.
 It is rare and highly improbable that Heterochromia be contracted in other
ways though a few cases have been shown where a bleaching of the eyes
can cause a dramatic color change via intense light.

6. Safety risks?
 There is no known safety hazards of having Heterochromia.
 The discoloration or pigment levels in the eyes affected have shown to
have no foreseeable weakness to sun, or light of any kind and have no
affect to everyday life.
 The only concern involved at all regarding Heterochromia is in the way in
which it was acquired I.e. a virus, traumatic injury to the eyes or face and
newborn birth complications.

7. Facts on Heterochromia
 Heterochromia in all forms has always been interesting to view. Typically
those affected with it have so many variances of the same forms that it is
rare to find two exactly the same.
 An uncommon occurrence when some one has Heterochromia is to find
multiple forms in the same person. It is possible to have both Full and
Central or Central and Sectoral Heterochromia and any variation produces
an interesting array of designs and colors.
 Perhaps one of the most interesting facts on this intriguing mutation is that it
is not limited to simply humans. Many animals like horses, cats, dogs, bears
and other mammals have been known to have it before all with the same
classifications but each with their own variations to pattern and color.

8. In Summary
 Heterochromia is a rare and beautiful mutation that mammals are subject
to.
 It has no health concerns that are caused from it but can sometimes be the
aftermath of something affecting the body like a disease or a traumatic
incident.
 It can come in many different ways and yet still be so similar amongst all
effected by it.

9. Sources:
 All images are tagged with sources as hyperlinks during presentation.
 "Heterochromia (Eyes of different colors)." . N.p.. Web. 7 Apr 2013.
http://www.bios.niu.edu/johns/diff_eye.htm
 "What Is Heterochromia Iridum?." wiseGEEK. wiseGEEK. Web. 7 Apr 2013.
http://www.wisegeek.com/what-is-heterochromia-iridum.htm
 "Heterochromia." MedicinePlus. U.S. National Library of Medicine, 22 Mar
2013. Web. 7 Apr 2013.
http://www.nlm.nih.gov/medlineplus/ency/article/003319.htm
 "Exactly how rare is central heterochromia." WikiAnswers. N.p., 22 Jan 2011.
Web. 7 Apr 2013.
http://wiki.answers.com/Q/Exactly_how_rare_is_central_heterochromia