Can Your Eyes Change Color? Exploring Temporary Changes and Medical Conditions

What Determines Your Eye Color?

Eye color is determined by the amount of melanin in the iris—the colored part of your eye surrounding the pupil. Melanin regulates how much light enters your eye, and the more melanin present, the darker the eye color will be. People with brown eyes have higher melanin levels, while those with blue or green eyes have less melanin.

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

Your parents' eye color plays a significant role in determining yours. For instance, if both parents have blue eyes, it's likely that their child will have blue eyes as well. However, if one parent has blue eyes and the other has brown, the child’s eye color could vary and be less predictable.

It’s also possible for a child’s eye color to differ from both parents, influenced by other genetic factors from extended family. For example, a child born to two brown-eyed parents might inherit blue eyes if their grandparents had blue eyes.

Newborns often experience changes in their eye color during the first few months. It's normal for a baby’s eye color to darken as melanin production increases during this period. This is because melanocytes, the cells responsible for producing melanin, remain active in the eyes for several months after birth.

Temporary vs. Permanent Eye Color Changes: How to Tell the Difference

It is rare for adults to experience dramatic changes in eye color, but subtle shifts can occur over time. For example, prolonged sun exposure can cause eyes to darken slightly, and as some individuals age, their eye color may lighten. However, for most people, eye color remains stable, and any noticeable change should be examined by an eye care professional, as it could indicate an underlying health issue.

Various factors can influence how your eye color appears or cause it to change temporarily. Let’s take a look at some of the common causes of temporary changes and distinguish them from permanent shifts. 

Medical Reasons Behind Changes in Eye Color

While genetics are the primary determinant of eye color, certain medical conditions can lead to noticeable changes in the appearance of your eyes. Here are a few conditions that could cause such changes:

Eye Injury

An eye injury—whether from blunt force trauma, penetrating wounds, or chemical burns—can disrupt the iris and its blood vessels, leading to visible changes in eye color. Here’s what might happen:

• Iron (siderosis) or calcium (chalcosis) deposits can accumulate on the iris, causing reddish-brown or white patches. 

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

If eye color changes following an injury, it could indicate further complications such as angle-recession glaucoma or the presence of foreign objects in the eye. It’s important to consult an eye care professional right away to prevent additional issues. 

Lisch Nodules

Lisch nodules are small, brown spots that appear on the iris and are most commonly associated with neurofibromatosis, a genetic disorder that affects nerve tissue growth. While Lisch nodules typically don’t affect vision, their presence can cause the iris to appear darker or speckled, particularly in people with blue or green eyes. As neurofibromatosis requires ongoing medical care, it's essential to seek professional medical advice if you notice these changes.

Fuchs Heterochromic Iridocyclitis (FHI)

Fuchs Heterochromic Iridocyclitis (FHI) is a rare condition that causes inflammation in the iris, resulting in a loss of pigmentation and noticeable changes in eye color. In addition to changing the color of the eyes, FHI may also cause cataracts, and if left untreated, it can lead to glaucoma. Since its symptoms are often subtle, FHI may not be diagnosed until problems like blurred vision or increased eye pressure occur. Early diagnosis is important to prevent further complications.

Changes in Color Due to Medication

Some medications, especially those used to treat glaucoma, can gradually darken eye color. Prostaglandin analogs, such as latanoprost, bimatoprost, and travoprost, are known to cause these changes, particularly when used in only one eye. While the color change is generally harmless, it can be permanent. If you are concerned about any changes in eye color, it’s essential to discuss the potential risks and benefits with your doctor.

Horner’s Syndrome

Horner’s syndrome is a rare condition that can result from nerve damage, often caused by a stroke or injury. This condition affects the sympathetic nervous system and can cause changes in the iris and pupil, which may alter the appearance of your eye color. A common symptom of Horner’s syndrome 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 irregularities that can change its color. This condition can also lead to increased eye pressure, resulting in secondary glaucoma that may require surgery. ICE syndrome typically affects middle-aged women and often presents with subtle changes in eye color, but it can lead to more serious complications if left untreated.

Cosmetic Eye Color Changes

If you’ve ever wanted to change your eye color for a new appearance, several safe and temporary methods can help you achieve the desired effect. Unlike medical conditions that cause permanent changes, these cosmetic options allow you to shift your eye color in a reversible manner.

• Prescription Colored Contact Lenses: Colored contact lenses are one of the best options for temporarily altering your eye color. Available in a variety of shades, they can either enhance your natural color or provide an entirely new look. It’s important to ensure that your colored contacts are properly fitted and cleaned to avoid irritation or damage. Always follow your eye care provider's instructions for cleaning and maintenance to achieve the best results. 

• Makeup and Lighting: If you prefer not to wear colored contacts, makeup and lighting can be used to accentuate or slightly alter the appearance of your eyes. For example, warm-toned eyeshadows, like gold or copper, can make brown eyes appear brighter, while shades of plum or green can enhance the unique hues of hazel or green eyes. Additionally, soft lighting, such as using soft-box lights, can intensify the natural color of your eyes in photos. Digital filters can also be used to change the eye color in social media photos or videos, providing a temporary and virtual change.