Can the eyes really turn purple?
The myth has been traced back to 2005, though it may have been spread earlier. People with the fake condition are said to be able to live to 150, and they allegedly have:
- purple eyes, with the color present from birth or developing shortly after
- pale skin
- perfectly proportioned bodies
- an absence of body hair
- high levels fertility, but without menstruation in women
- excellent immune systems
- very little bodily waste
While Alexandria's genesis is a complete fabrication, the following real conditions can change the color of the iris.
Conditions that change eye color
The iris is the colored ring that surrounds the eye's pupil. It controls the amount of light that enters the eye.
Natural changes with age
A person cannot be born with purple eyes, and Alexandria's genesis is not a real condition.
Most babies are born with brown eyes. However, many of Caucasian heritage initially have blue or gray eyes. This color may darken over time, to become green, hazel, or brown. Infants with brown eyes rarely experience changes in iris color, although the shade of brown may become more prominent.
A change in iris color occurs because of a protein called melanin, which is also present in the hair and skin. Cells called melanocytes produce melanin in response to light exposure.
Melanocytes become more active during the first year of life, explaining the change in an infant's eye color.
Usually, changes in eye color will have stopped by the age of 6, though some people experience them throughout adolescence and adulthood. Research suggests that this phenomenon affects 10–15 percent of people of Caucasian heritage.
People with heterochromia iridis have eyes of different colors.
Another form of the condition, called segmental heterochromia, causes color variations within the same iris.
Most of the time, heterochromia occurs sporadically and is not caused by another disorder.
In rare cases, it may be linked to other conditions, such as:
- Horner's syndrome
- Parry-Romberg syndrome
- Sturge-Weber syndrome
- Waardenburg syndrome
Fuchs' heterochromic uveitis (FHU)
Also known as Fuchs' heterochromic iridocyclitis, this rare condition is characterized by long-term inflammation of the iris and other parts of the eye.
FHU causes a change in eye color. The iris usually becomes lighter, though it may darken in some cases. FHU typically affects one eye, but 15 percent of people experience a change in both, according to the American Uveitis Society.
Horner's syndrome, or Horner-Bernard syndrome, refers to a group of symptoms that affect one side of the face. These include:
- decreased pupil size
- delayed opening of the pupil in dim light
- a drooping eyelid
- reduced sweating on one side of the face
The difference in pupil size between the affected and unaffected eyes can give the appearance of different eye colors.
The iris of the affected eye may also be lighter in color when the syndrome develops in babies under 1 year old.
Horner's syndrome is caused by a disruption in a nerve pathway leading from the brain to one eye and side of the face. It often results from damage induced by:
Sometimes no underlying cause can be found.
Glaucoma occurs when the optic nerve is damaged.
Glaucoma is a group of eye conditions caused by damage to the optic nerve. This damage is often linked to abnormally high pressure in the eye. Glaucoma can lead to vision loss if left untreated.
It is estimated that over 3 million Americans have glaucoma, though not all are aware of it.
One type, pigmentary glaucoma, causes the pigmentation in the iris to fall away in tiny granules.
These granules build up in the eye's drainage channels, preventing fluid from seeping out and increasing pressure in the eye.
This may lead to abnormalities in the iris, though the color of the eyes will not completely change. Treatment involving medication, lasers, or surgery can reduce the buildup of pressure, but it is difficult to prevent the release of pigment.
Tumors of the iris
Tumors may grow behind or within the iris. The majority are cysts or pigmented lesions similar to moles, called nevi. Other tumors may be cancerous.
Tumors in the iris usually cause no symptoms, but some people with nevi may notice changes in their eye color.
Even when no other symptoms are present, if a person suspects that they have a tumor they should see a doctor, especially if a nevus:
- changes shape or color
- becomes bigger
- interferes with the pupil
Treatments include radiation and surgery.
Medicated eye drops
Some medicated eye drops used to treat glaucoma can lead to changes in eye color.
Medications known as prostaglandin analogs, such as latanoprost (Xalatan) and bimatoprost (Lumigan), can cause light-colored eyes to darken. They may also lead to other changes in the eyes' appearance.
Bimatoprost can act as an eyelash enhancer, and it is marketed under the name Latisse for this purpose. When applied to the eyelashes, Latisse can encourage growth, but it may also increase brown pigmentation in the eyes. This effect is likely permanent.
Latisse can cause the skin of the eyelids to darken as well, though this effect usually goes away when a person stops using the product.
When to see a doctor
Any changes in the appearance of the eye or vision should be assesed by a doctor.
Anyone who notices changes in the color of one or both eyes should see a doctor. Changes unrelated to color should also be investigated, as they may signal an underlying condition.
A person should also seek treatment anytime they experience:
- reduced vision
- floating spots in the field of vision
- redness of the eyes
Alexandria's genesis is a myth about the existence of "perfect" human beings who have purple eyes and other unrealistic attributes.
However, many real conditions and some medications can change the iris' color. Eye color may also change naturally over time, especially in early childhood.
These changes may be harmless but should always be checked by a doctor. If there is a serious underlying cause, such as glaucoma or a malignant tumor, early treatment can improve a person's outlook.