Can Your Eyes Change Color? Separating Fact from Fiction

What Determines Your Eye Color?

Eye color is determined by the amount of melanin, a pigment, in the iris, the colored part of your eye that surrounds the pupil. Melanin helps control how much light enters the eye. The more melanin present, the darker the eye color will be. For example, individuals with brown eyes have higher levels of melanin, while those with blue or green eyes have lower amounts.

The level of melanin in your eyes is inherited from your parents and determined by specific genes. These genes not only influence eye color but also contribute to other characteristics like hair color and skin tone.

Your parents' eye colors play a significant role in determining your own. For example, if both parents have blue eyes, it’s more likely that their child will also have blue eyes. However, if one parent has blue eyes and the other has brown eyes, the child’s eye color may vary and is less predictable.

It’s also possible for a child’s eye color to be different from both parents due to the influence of other genetic factors. For example, a child with two brown-eyed parents might inherit blue eyes if their grandparents had blue eyes.

Newborns' eyes often undergo changes in color over time. It's normal for a baby’s eye color to darken during the first few months as melanin production increases. This change happens because melanocytes, the cells responsible for producing melanin, continue to function in the eyes for several months after birth. 

Temporary vs. Permanent Eye Color Changes: Understanding the Difference

While significant changes in eye color are uncommon in adults, subtle shifts can occur over time. For example, exposure to sunlight can cause eyes to darken slightly, while aging may lead to lighter eye colors in some individuals. In most cases, however, your eye color remains unchanged, and any notable shift should be evaluated, as it could signal a health issue.

Several factors can cause your eye color to appear different or seem to change temporarily. Let’s examine some common reasons behind these changes and how they differ from permanent shifts.

Medical Reasons Behind Changes in Eye Color

Although genetic factors are the primary cause of eye color, certain medical conditions can lead to changes in the appearance of your eyes. Below are some of the conditions that may cause such changes:

Eye Injury

An eye injury, whether caused by blunt trauma, a penetrating injury, or a chemical burn, can disrupt the iris tissue or its blood vessels, leading to noticeable changes in your eye color. There are two potential outcomes:

• Iron deposits (siderosis) or calcium deposits (chalcosis) can accumulate on the iris, giving it a reddish-brown or white appearance. 

• The iris tissue may thin, allowing more light to reflect off the eye’s inner layers, making the eye appear lighter. 

If your eye color changes after an injury, it may indicate underlying conditions like angle-recession glaucoma or retained foreign objects. Any eye injury accompanied by a color change should be promptly evaluated by an eye doctor to prevent further complications. 

Lisch Nodules

Lisch nodules are small brown spots on the iris, commonly associated with neurofibromatosis, a genetic condition affecting nerve tissue growth. Although Lisch nodules usually don’t affect vision, their presence can cause a speckled or darker appearance in the iris, particularly in individuals with blue or green eyes. Since neurofibromatosis requires ongoing medical management, it’s important to consult with a healthcare professional if you notice these changes.

Fuchs Heterochromic Iridocyclitis (FHI)

Fuchs Heterochromic Iridocyclitis (FHI) is a rare condition that causes inflammation in the iris, leading to a loss of pigmentation and a visible change in eye color. In addition to changing eye color, FHI can cause cataracts and, if left untreated, may result in glaucoma. Because its symptoms are often subtle, FHI might not be diagnosed until more noticeable vision problems, such as blurred vision or increased eye pressure, occur.

Changes in Color Due to Medication

Certain medications, especially those used to treat glaucoma, can cause gradual darkening of the eye color. Prostaglandin analogs like latanoprost, bimatoprost, and travoprost are known to alter eye color, particularly when used in one eye. While these color changes are generally harmless, they can be permanent. It’s important to discuss any concerns with your doctor and weigh the benefits and risks of continuing treatment.

Horner’s Syndrome

Horner’s syndrome is a rare condition often caused by nerve damage, usually due to a stroke or injury. It affects the sympathetic nervous system and can lead to changes in the iris and pupil. One of the visual effects is that the affected pupil may appear larger or smaller than the other, which can make the eye color look different. In addition to these changes, Horner’s syndrome may also cause iris depigmentation.

Iridocorneal Endothelial Syndrome (ICE)

ICE syndrome is a rare disorder where cells from the cornea (the clear outer layer of the eye) migrate to the iris, creating spots or irregularities that affect its color. This condition can also cause increased eye pressure, leading to secondary glaucoma, which may require surgical treatment. ICE syndrome typically affects middle-aged women and often begins with subtle eye color changes, but can lead to serious complications if left untreated.

Cosmetic Eye Color Changes

If you're looking to alter your eye color temporarily for a new look, there are several safe options available that can give you the change you desire without permanent effects. Unlike medical conditions that cause lasting eye color changes, these cosmetic options allow for a reversible transformation.

• Prescription Colored Contact Lenses: Colored contact lenses are one of the best ways to change your eye color temporarily. Available in various colors, these lenses can enhance your natural eye color or provide an entirely different shade. However, it is crucial to ensure the lenses are properly fitted and cleaned to avoid irritation or damage. Always follow the care instructions provided by your eye care professional for safe use. 

• Makeup and Lighting: If you prefer not to wear contact lenses, makeup and lighting can help accentuate or change the appearance of your eyes. Warm-toned eyeshadows, such as gold or copper, can enhance the vibrancy of brown eyes, while plum or green shades can highlight the flecks in hazel or green eyes. Using certain lighting techniques, like soft-box lights, can amplify the natural color of your eyes in photos. Additionally, digital filters can alter eye color for online images or videos, providing a temporary cosmetic effect.