Most people will have the same eye color from when they learn to walk until the end of their lives. In the first months, a newborn’s eyes are blue-gray. As the eye pigment develops, the eyes become darker in color. Most babies acquire their definitive color at around 9 months old.
However, there are a few things that can influence eye color throughout life, and it is very important to schedule an ophthalmological examination if you notice any changes in this regard.
Read on to find out what determines the eye color, what possible health problems can influence the shade of the iris, and how you can change eye color – temporarily or permanently.
Factors that determine eye color
Eye color is determined by the iris, a part of the eye that is genetically controlled. The iris is located inside the eye, and in its center is the pupil. The color of the iris varies depending on the amount of pigment (melanin) it contains. The higher the level of melanin, the darker the color of the iris.
- Brown eyes are the most common. It is estimated that between 60 and 80% of the world’s population has this iris color. The increased amount of melanin gives the eyes a darker color. Brown eyes are more commonly found in regions with a warm climate, as melanin provides protection against solar radiation for the skin, hair, and eyes.
- Less than 10% of the population has blue eyes. This shade is predominant in northern Europe. The very small amount of melanin and light reflection actually determine this color.
- Green eyes are even rarer. Approximately 2% of the population has green eyes. This shade is caused by a small amount of melanin, combined with a pigment called lipochrome.
- Black, gray, amber, pink, violet, red or pink, are extremely rare shades.
The color of the iris is determined by the combination of the parents’ genes. There are so many possible combinations that it is impossible to predict the color of the child’s iris. It may not resemble the mother’s or father’s iris.
Natural changes in the eye color in babies and adults
The color of the eyes can change over time, but only to a small extent.
Changes in eye color in babies usually occur in the first months of life. During this time, the body produces melanin, which later gives the eyes a darker color.
The expansion or contraction of the pupil can also lead to minor changes in the color of the iris. These can occur when a person:
- Focuses their gaze
- Spends time in very dark or very bright areas
- Experiences strong emotions
Sometimes, the color of the eyes lightens as one ages, as it comes with a whitening effect on the iris. This is normal and should not be a cause for concern.
Ophthalmological disorders associated with changing eyes
Changing eye color can be harmless or it can be a sign of an ophthalmological disorder that requires treatment. These problems can be related to the iris, other parts of the eye, or certain medications.
Problems related to the iris:
- Spots on the iris: These appear on the surface of the iris usually as a result of sun exposure. They are common and most of the time harmless, similar to the freckles on the skin.
- Nevi on the iris: These are larger spots or dark formations on the surface of the iris, similar to moles. Nevi are caused by pigment cells called melanocytes. They are usually harmless and grow slowly, but they can pose a risk of cancer. Nevi are not as common as spots on the iris and should be monitored by a specialist.
- Lisch nodules are small brown growths that grow on the iris. They are usually associated with a condition called neurofibromatosis (a disorder of the nervous system that causes the growth of small tumors on nerve cells throughout the body). The disorder is genetic and can be inherited in the family. It usually does not affect vision. People with neurofibromatosis can live normal lives as the nodules do not affect vision. However, regular check-ups are essential to detect possible complications in time.
- Fuchs’ heterochromic iridocyclitis is an inflammation of certain structures in the front part of the eye, including the iris. The cause of the disorder is unknown and sometimes it can be difficult to treat. The symptoms include: iris atrophy, loss of pigment in the iris resulting in a change in eye color, cataract and inflammation in the eye. Sometimes, Fuchs’ heterochromic iridocyclitis can lead to glaucoma, which – if left untreated – can cause serious vision problems.
- Iridocorneal endothelial syndrome is a very rare combination of three diseases that develop together, affecting the iris and cornea. The cells on the cornea detach and migrate towards the iris. This appears as spots on the iris, affecting the eye color. Iridocorneal endothelial syndrome usually affects only one eye and leads to glaucoma.
- Pigment dispersion syndrome involves the loss of pigment from the back surface of the iris, with those cells migrating to other parts of the eye. They can block the eye’s drainage angle, increasing intraocular pressure. It is more commonly found in young men who also suffer from myopia. Usually, patients do not have symptoms until the condition progresses to pigmentary glaucoma, which causes blurred vision and other changes in vision.
- Uveitis is an inflammation of the middle layer of the eyeball. The condition is usually caused by inflammation, infection, trauma, or exposure to toxins. Patients may notice a change in eye color if the iris becomes detached from the lens and changes the size or shape of the pupil. Uveitis requires urgent treatment.
- Horner’s syndrome is a rare condition that usually occurs following a stroke, tumor, or spinal cord injury that affects the facial nerves. Symptoms include drooping eyelids, uneven pupil sizes, and inability to sweat on the affected side of the face. When one pupil is much larger than the other, the eye color appears different. In very rare cases, Horner’s syndrome can occur in newborns or infants. The condition can also cause a change in eye color due to iris depigmentation.
- Injuries or trauma to the eye can affect the iris, causing tissue loss. This tissue loss can cause the eye color to appear different.
- Anisocoria or changes in pupil size can influence eye color. In reality, the color remains the same, but if the pupil is dilated, less of the iris shade can be seen. A dilated pupil can be a symptom of a serious condition such as a stroke or brain injury. It can also be the result of an eye injury. In some cases, the pupil returns to its normal size with treatment.
Issues related to other parts of the eye:
- “Arcus senilis” is a bluish or whitish ring on the cornea, resulting from the accumulation of a fatty substance called lipids. The condition is called gerontoxon, usually harmless and commonly seen in the aging process. Most elderly people have some degree of arcus senilis.
- Kayser-Fleischer rings are greenish-orange rings in the cornea, which occur in Wilson’s disease (a condition related to elevated levels of copper in the body). It is very rare and requires medical treatment.
- Hyphema represents the presence of blood inside the eye, usually caused by trauma or surgery.
- Cataract causes the lens of the eye to appear cloudy or gray. This vision problem is common in the aging process. It is treated through cataract surgery.
Medication-related problems:
Some medications used for glaucoma can cause changes in eye color. Usually, it is about prostaglandins, which slightly darken the natural shade of the iris. Discuss any changes you notice with your doctor to choose the best ophthalmological treatment.
Changing the eye color: Temporary and permanent options
If you want to change the color of your eyes, there are temporary or permanent methods available. Each comes with its own advantages and risks.
Temporary options
Colored contact lenses are the simplest way to change the color of your eyes for a short period of time.
There are three types of lenses available, depending on how drastic you want the change to be.
- Visibility lenses
- They are lightly colored.
- They have a minimal effect if a person’s eyes are already light in color.
- Enhancement lenses
- They are semi-opaque.
- They don’t completely change the eye color, but they can enhance it, making it stand out more.
- Opaque lenses
- Through these lenses, the iris is completely colored, allowing a person to completely change the color of its eyes.
- Opaque lenses are available in various colors (purple, blue, green, brown, brown with a green shade, gray, etc.)
Permanent options
If you want the change in eye color to be permanent, there are ophthalmological surgeries that you can resort to. It is extremely important to go to a specialist who can guide you through this process. Dr. Holhoș clinics are renowned for top doctors and state-of-the-art ophthalmological technology.
- Iris implant
The technique was developed in 1956 to repair iris defects caused by injury, infection, or congenital defects such as ocular albinism. The intervention is less commonly used for cosmetic purposes, due to possible risks.
The surgery involves the insertion of a prosthetic iris to cover the natural iris. To implant the iris, the ophthalmologist makes a small incision in the cornea where it meets the sclera (the white part of the eye). The silicone iris is folded and inserted through the incision. Then, the prosthetic is unfolded and sutured over the natural iris.
The procedure requires local anesthesia and is done on an outpatient basis, so no hospitalization is needed.
Most iris implants are available in standard colors such as blue, green, brown, and black.
The iris implant comes with a series of possible complications:
- Glaucoma (a progressive condition that affects the optic nerve)
- Cataract (clouding of the lens)
- Eye infection (which can lead to corneal ulcers and scarring)
- Reduced vision
- Blindness
Surgery is contraindicated for people with glaucoma and diabetic retinopathy.
- Laser Keratopigmentation
Changing the eye color with laser is possible through keratopigmentation. The procedure is also known as “corneal tattooing”. This does not change the color of the iris, but adds color to the cornea to mask the iris shade.
Keratopigmentation uses laser to create a series of circular tunnels with uniform depth in the cornea. Then, colored dye is injected into those tunnels. The technology ensures a more uniform distribution of color than traditional needle puncturing techniques.
Keratopigmentation is performed with anesthetic eye drops. The head will be fixed in a device to maintain a fixed position, and an instrument will keep the eyelid open and prevent blinking. The procedure can be uncomfortable, but it causes little to zero pain.
The intervention has a relatively short recovery time (2-3 days), as the corneal surface is not affected and the pigment is contained in the corneal tunnels. Full recovery and healing can take between 1 and 3 weeks. You can expect mild discomfort on the first day, followed by sensitivity to bright lights for approximately 3 days.
Despite the precision of this technique, keratopigmentation is not without risks. Although every effort is made to stabilize the eye and head, any involuntary movement can lead to errors and possible injuries. Other complications may occur after the procedure:
- Inconsistent eye color (caused by uneven distribution of the pigment)
- Fading of color (due to pigment migration or leakage into the corneal space)
- Corneal perforation (a perforation of the cornea that can lead to fluid leakage and changes in vision)
- Light sensitivity (caused by abnormal light refraction)
- Reaction to dye (which can lead to uveitis – inflammation of the middle layer of the eye – or corneal neovascularization – formation of new blood vessels in the cornea)
- Bacterial eye infection (which increases the risk of corneal ulcers and scarring)
Laser keratopigmentation is contraindicated for people with corneal diseases or those who have undergone refractive surgery.
- Laser depigmentation
Laser depigmentation is used to darken the color of the eyes by targeting the cells that produce melanin.
The procedure involves multiple sessions. Low-energy laser beams heat up the brown pigment on the surface of the iris and reveal the blue or green color inside. The laser passes through the cornea without causing any damage. Numbing is done with anesthetic eye drops and is painless.
Changing the eye color with laser depigmentation is not immediate. It can take up to 4 weeks for the body to absorb the brown layer and fully reveal the blue or green color from within. During this time, slight vision disturbances, red eyes, tearing, and sensitivity to light may occur. If the iris becomes inflamed, the problem tends to be short-lived, causing headaches, abnormal pupils, and sensitivity to light.
Compared to other techniques for changing eye color, laser depigmentation presents the fewest risks. However, there are a few possible complications:
- Inflammation of the iris (usually mild and short-lived)
- Light sensitivity (caused by abnormal dilation of the pupils, usually short-lived)
- Undesired eye color (the green or blue shade can only be revealed after the brown layer above is removed).
Laser depigmentation is contraindicated for those with glaucoma.
If you notice sudden changes in the color of one or both eyes, go to an ophthalmologist as soon as possible. Major changes in iris pigment can indicate diseases such as Horner’s syndrome, pigmentary glaucoma, iris melanoma, or Fuchs heterochromic iridocyclitis. All of these require urgent treatment.
