Can Your Eyes Change Color? Myths and Medical Reasons

What Determines Your Eye Color?

Eye color is determined by the amount of melanin in the iris—the colored part of your eye that surrounds the pupil. Melanin helps regulate the amount of light that enters your eye, and the more melanin present, the darker the eye color will be. For instance, people with brown eyes have more melanin, while those with blue or green eyes have less.

The amount of melanin in your eyes is inherited from your parents and regulated by specific genes. These same genes affect other traits such as skin and hair color.

Your parents’ eye colors play a significant role in determining your eye color. For example, if both parents have blue eyes, there is a high chance their child will also have blue eyes. However, if one parent has blue eyes and the other has brown, the child’s eye color may be less predictable.

It’s also possible for a child’s eye color to differ from both parents, as genetic influences from extended family members may come into play. For example, a child with two brown-eyed parents might inherit blue eyes if their grandparents had blue eyes.

Newborns’ eye color can change during the first few months. It’s normal for babies’ eyes to darken as melanin production increases in this early period. This is because melanocytes—the cells responsible for producing melanin—continue to function for several months after birth. 

Temporary vs. Permanent Eye Color Changes: Spotting the Difference

While it’s uncommon for adults to experience drastic changes in eye color, subtle shifts can occur over time. For example, prolonged exposure to the sun may cause the eyes to darken slightly, while aging may lead to a lightening of eye color in some individuals. However, for most people, eye color remains stable, and any noticeable change should be investigated as it could indicate an underlying health condition.

Several factors can influence how your eye color appears or change temporarily. Let’s explore the common causes behind temporary changes and how they differ from permanent shifts.

Medical Reasons Behind Changes in Eye Color

Although genetics are the primary factor influencing your eye color, certain medical conditions can alter the appearance of your eyes. Here are a few conditions that may result in changes in eye color:

Eye Injury

Eye injuries, whether from blunt trauma, penetrating wounds, or chemical burns, can cause changes to the iris and its blood vessels, leading to visible shifts in your eye color. The following may occur:

• Iron (siderosis) or calcium (chalcosis) deposits can form on the iris, resulting in a reddish-brown or white tint. 

• Thinning of the iris tissue may allow more light to reflect from deeper layers of the eye, making the eye appear lighter. 

If you notice a change in eye color after an injury, it could indicate other problems, such as angle-recession glaucoma or retained foreign bodies. It’s important to consult with an eye care professional immediately to prevent any potential complications. 

Lisch Nodules

Lisch nodules are small brown spots that can develop on the iris. They are commonly associated with neurofibromatosis, a genetic condition that affects nerve tissue growth. While these nodules typically do not impact vision, they can cause the iris to appear speckled or darker, especially in people with blue or green eyes. As neurofibromatosis requires ongoing medical management, it’s important to seek medical advice if you notice these changes in your eyes.

Fuchs Heterochromic Iridocyclitis (FHI)

Fuchs Heterochromic Iridocyclitis (FHI) is a rare condition that causes inflammation in the iris and leads to a loss of pigmentation, resulting in changes to eye color. Along with altering eye color, FHI can cause cataracts, and if left untreated, it may lead to glaucoma. As FHI symptoms can be subtle, it is often not diagnosed until vision problems like blurred vision or increased intraocular pressure arise. Early diagnosis and treatment are crucial.

Changes in Color Due to Medication

Certain medications, particularly those prescribed for glaucoma, may cause gradual darkening of the eyes. Prostaglandin analogs like latanoprost, bimatoprost, and travoprost can cause these color changes, especially when used in one eye. While these changes are generally harmless, they can be permanent. If you are concerned about any changes, it’s essential to discuss the potential risks and benefits of your medication with your doctor.

Horner’s Syndrome

Horner’s syndrome is a rare condition caused by nerve damage, often resulting from a stroke or injury. It affects the sympathetic nervous system and can cause changes in both the iris and pupil, which may make your eye color appear different. A common symptom is that one pupil may appear smaller or larger than the other, and iris depigmentation can also occur.

Iridocorneal Endothelial Syndrome (ICE)

Iridocorneal Endothelial Syndrome (ICE) is a rare disorder where cells from the cornea (the clear outer layer of the eye) migrate to the iris, causing spots or other irregularities that can alter its color. The condition can also lead to increased eye pressure, resulting in secondary glaucoma that may require surgical intervention. ICE syndrome typically affects middle-aged women and often begins with subtle changes in eye color, but it can lead to serious complications if left untreated.

Cosmetic Eye Color Changes

If you’ve ever considered changing your eye color for a fresh look, several safe, non-permanent methods are available to help you achieve the change. Unlike medical conditions that cause lasting changes, cosmetic options allow for a temporary and reversible shift in eye color.

• Prescription Colored Contact Lenses: Colored contact lenses are an excellent option for altering your eye color. Available in a wide array of shades, they can enhance your natural color or create an entirely new appearance. It’s crucial to ensure your colored contacts are properly fitted and cleaned to avoid irritation or harm. Always adhere to your eye care professional's guidelines for cleaning and maintenance to ensure the best results. 

• Makeup and Lighting: If you prefer not to wear colored contacts, makeup and lighting offer alternatives to enhance or modify your eye color. Warm-toned eyeshadows like copper or gold can make brown eyes appear more vibrant, while plum or green tones can bring out the unique hues in hazel or green eyes. Additionally, soft lighting, such as using soft-box lights, can make your natural eye color appear more intense in photographs. Digital filters can also be used to modify your eye color in social media pictures or videos for a temporary, virtual change.