Can Your Eyes Change Color? Separating Myth from Reality

What Determines Your Eye Color?

Eye color is primarily determined by the amount of melanin present in the iris—the colored part of your eye that surrounds the pupil. Melanin plays a role in regulating how much light enters your eyes, and the more melanin in the iris, the darker your eye color will be. For instance, individuals 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 influenced by specific genes. These same genes also affect other physical traits such as your hair and skin color.

Your parents’ eye color plays a significant role in determining your own. For example, if both parents have blue eyes, it’s highly likely 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 may vary and is less predictable.

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

Newborns' eye color often changes in the first few months. It's normal for babies’ eyes to darken as melanin production increases during this time. This change occurs because melanocytes—the cells that produce melanin—continue to be active in the eyes for months after birth. 

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

While significant changes in eye color are rare in adults, some subtle shifts may happen over time. For instance, prolonged sun exposure can cause your eyes to darken a bit, while aging may cause the eye color to lighten for some individuals. However, in most cases, your eye color remains the same, and any noticeable changes should be investigated, as they could point to an underlying health condition.

Various factors may cause your eye color to appear different or change temporarily. Let’s explore the common causes and how they differ from permanent changes. 

Medical Reasons Behind Changes in Eye Color

Although genetics are the primary determinant of eye color, some medical conditions can result in changes to the appearance of your eyes. Below are several conditions that can cause such changes:

Eye Injury

An injury to the eye, whether from blunt trauma, a penetrating wound, or a chemical burn, can affect the iris and its blood vessels, causing visible changes in your eye color. Here’s what can happen:

• Iron (siderosis) or calcium (chalcosis) deposits may form on the iris, giving it a reddish-brown or white tint. 

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

If you notice a change in eye color following an injury, it could signal other issues, such as angle-recession glaucoma or retained foreign objects. Any eye injury with color changes should be assessed by an eye care professional immediately to avoid complications. 

Lisch Nodules

Lisch nodules are small, brown spots that appear on the iris and are often associated with neurofibromatosis, a genetic condition affecting nerve tissue growth. Although Lisch nodules typically do not affect vision, their presence can cause the iris to appear darker or speckled, particularly in individuals with blue or green eyes. Neurofibromatosis requires ongoing medical management, so it’s important to consult with a healthcare provider if you notice these changes. 

Fuchs Heterochromic Iridocyclitis (FHI)

Fuchs Heterochromic Iridocyclitis (FHI) is a rare eye condition that causes inflammation in the iris, leading to a loss of pigmentation and noticeable changes in eye color. In addition to changes in eye color, FHI can cause cataracts and, if left untreated, may lead to glaucoma. The subtle symptoms of FHI may not be noticed until more serious issues like blurred vision or increased intraocular pressure occur, making early diagnosis important.

Changes in Color Due to Medication

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

Horner’s Syndrome

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

Iridocorneal Endothelial Syndrome (ICE)

Iridocorneal Endothelial Syndrome (ICE) is a rare disorder where cells from the cornea (the clear outer layer of the eye) move to the iris, creating spots or other irregularities that affect its color. The condition can also lead to increased eye pressure, which may cause secondary glaucoma that requires surgical treatment. 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 look, there are several safe methods to do so without any lasting effects. Unlike permanent eye color changes caused by health conditions, these cosmetic options are reversible and can be easily adjusted.

• Prescription Colored Contact Lenses: One of the best ways to temporarily alter your eye color is by using colored contact lenses. These lenses come in a wide range of colors and can either subtly enhance your natural eye color or completely transform it. It’s essential to ensure that your colored contacts are fitted correctly and cleaned properly to prevent irritation or damage. Always follow your eye care professional's guidelines for proper use and maintenance. 

• Makeup and Lighting: For those who prefer not to wear contact lenses, makeup and lighting can be used to enhance or change the look of your eyes. For example, warm tones like gold or copper eyeshadow can make brown eyes appear brighter, while purple or green shades can bring out the unique flecks in hazel or green eyes. Additionally, soft lighting, such as using soft-box lights, can intensify your natural eye color in photos. Digital filters can also be used to modify your eye color in social media images or videos, creating a temporary effect.