Blue eyes turning grey is a natural part of the aging process for some people. As we get older, the pigment in our irises can start to fade or thin out, causing the eye color to lighten over time. Here are some key facts about why and how blue eyes can turn grey:
The Biology Behind Blue Eyes
Blue eyes get their color from the presence of melanin pigment in the front layer of the iris. The specific melanin that influences eye color is called lipochrome – also known as the “blue” melanin. The more lipochrome melanin present, the darker and richer the blue color will be.
People with very little lipochrome have light blue or grayish blue eyes. Those with moderate amounts have medium-toned blue eyes. Lots of lipochrome leads to very dark navy blue eyes.
Melanin Loss and Thinning Over Time
As we age, the eye’s pigment cells start to gradually lose their melanin content. The lipochrome pigment particles also become smaller and more sparse in the iris. This leads to a dilution and lightening of the original eye color.
Additionally, the collagen fibers that make up the connective tissue “skeleton” of the iris start to thin out with age. This causes the iris to become more transparent. The combination of less pigment and a more sheer iris allows more light to penetrate and reflect back, creating a paler gray or light blue shade.
When Does the Color Change Occur?
There is no set timeline for blue eyes turning gray. Some people may notice it happening in their 30s or 40s, while for others it doesn’t occur until much later in life.
Here is an approximate breakdown of when graying of blue eyes may happen:
| Age Range | Likelihood of Color Change |
|---|---|
| 30s-40s | Possible for some; usually subtle lightening |
| 50s-60s | More common |