Brown eyes are the most common eye color in the world, with over half of the global population having shades of brown. Eye color is determined by genetics and the amount of melanin pigment in the iris. While eye color generally remains stable throughout life, some changes can occur naturally over time. One such change is brown eyes turning grey.
Grey eyes are less common than brown, but can develop from darker colors through a natural reduction of melanin. The change tends to be subtle and happen gradually over many years. A variety of factors impact whether brown eyes turn grey including age, ethnicity, injuries, and certain medical conditions.
How Eye Color Is Determined
Eye color is genetic and determined by how much of the pigment melanin is present in the iris. Melanin is produced by specialized cells called melanocytes. The more melanin, the darker the eyes appear. Brown eyes contain large amounts of melanin, while blue eyes have very little. Grey eyes fall somewhere in between.
There are two types of melanin that impact eye color:
– Eumelanin – A brown/black pigment that produces brown and black tones.
– Pheomelanin – A red/yellow pigment that produces red and yellow hues.
The specific amount of each type of melanin present determines the final eye shade. Most commonly, brown eyes contain a high concentration of eumelanin. Over time, the amount of melanin can change leading to subtle shifts in eye color.
Can Brown Eyes Turn Grey Naturally?
Yes, brown eyes can turn grey naturally in some individuals as they age. However, it tends to be a gradual, subtle shift over the course of many years and decades. The change occurs because melanin levels in the body decrease as we get older.
Key Factors That Impact Changes in Eye Color
There are several key factors that impact whether brown eyes will turn grey over time:
– Ethnicity – Those with darker pigmentation are less likely to experience changes. Brown eyes turning grey is most common in those with European ancestry and lighter complexions.
– Age – Eye color typically begins to lighten in a person’s 30s and 40s as melanin production starts decreasing. The most noticeable changes often occur after age 50.
– Injuries – Trauma to the eyes or head can sometimes lead to instantaneous changes in eye color depending on the type and severity of injury.
– Medical conditions – Certain conditions like pigmentary glaucoma and ocular albinism can also cause the iris to lose pigmentation.
Gradual Process Over Many Years
While movies and folklore suggest eyes can change color overnight, the natural shift from brown to grey is typically extremely subtle and happens incrementally over an extended period.
By age 65, many individuals with originally dark brown eyes may notice their eyes appear to have lightened a shade or two to a warmer brown or hazel. In some cases, by ages 80+ the eyes can take on a distinctly grey appearance. However, the process is so gradual most people do not notice it occurring.
Factors That Impact Melanin Levels Over Time
Aging and Genetics
As a person ages, the body produces less melanin pigment overall. The rate of melanin depletion, and whether it leads to lighter eye colors, depends on genetics:
– Those genetically predisposed to produce less melanin are more likely to experience changing eye colors over time.
– Conversely, those genetically programmed to produce higher levels of melanin maintain dark eyes throughout life as melanin only depletes to a certain level.
Certain environmental factors can impact melanin production over the years and may make brown eyes turning grey more likely:
– Sun exposure – Exposure to UV rays can reduce melanin levels. Less sun means less melanocyte stimulation. Those who spend more time indoors tend to maintain higher melanin levels.
– Smoking – Smoking is linked with decreased melanin production, potentially contributing to lighter eye colors.
– Medications – Certain drugs like chloroquine and quinine can bind to melanin with long-term use, leading to reduced pigmentation.
Some medical conditions are associated with reduced production of melanin, which can lead to brown eyes lightening over time:
– Vitiligo – Autoimmune condition causing patchy loss of melanin in the skin, hair, and eyes. Can lead to partly grey irises.
– Pigmentary glaucoma – Results in loss of melanin from the iris due to high eye pressure, causing gradual lightening.
– Ocular albinism – Genetic mutation leading to decreased melanin levels in the eyes over a lifetime.
Can Contacts or Surgery Lighten Brown Eyes?
While small natural shifts can occur with age, the only way to significantly and rapidly lighten brown eyes is through external intervention like colored contacts or surgical procedures.
Contact lenses with no prescription but added tinting or opaque grey color can make brown eyes appear lighter when worn. This effect is temporary and eyes return to their natural shade when contacts are removed.
Laser or Surgical Procedures
More permanent options exist to intentionally lighten brown irises:
– Bleaching – Involves using lasers or chemicals to reduce melanin levels in the surface layer of the iris. Generally not recommended due to side effects.
– Iris implants – Surgically placing a silicone iris implant in front of the natural iris. The implant can be customized with lighter pigments.
However, these invasive procedures carry substantial risk of infection, inflammation, or vision impairment. Most eye doctors advise against attempting to permanently alter natural eye color.
While eye color generally remains constant a person’s whole life, some gradual lightening can occur naturally over time. For brown eyes to turn grey, melanin production must slow significantly with age and genetics. While possible, the process tends to be subtle and not overtly noticeable. Rapid or significant lightening of brown irises within a short time frame is unlikely without external intervention from contacts or surgery. Maintaining good health and protective practices like limiting sun exposure and avoiding smoking can help delay or prevent the natural depletion of melanin levels. Overall eye color is a unique trait to cherish, whether it darkens or lightens over the years.
In summary, it is possible for brown eyes to naturally turn grey over time in some individuals, but the changes are typically extremely gradual. Aging, genetics, and environmental factors like sun exposure and smoking can all impact melanin levels and influence if and how much brown eye color will lighten into shades of grey. While colored contacts or invasive procedures can quickly alter brown eyes, natural shifts to grey happen slowly over decades in a minimally noticeable fashion, if at all, for most people. Learning to embrace the eye color you were born with is recommended, as eyes can tell a story and reflect someone’s ethnic heritage and genetic background.