Hunh. I was today years old when I learned:

…This is actually somewhat of a myth. Human eyes don’t typically change color more than once in a lifespan (usually during infancy). The same goes for people with > hazel eyes.

One part of this pervasive belief is based on the fact that people define “hazel” in a number of ways. It represents a range of colors ranging from brownish to greenish and even gray sometimes. > > Because of this, two people who have “hazel” eyes can actually have very dissimilar iris colors.

Another aspect of this particular eye color that probably causes confusion is the fact that eyes within the color range generally defined as “hazel” tend to have a higher degree of reflectivity than > > normal. This means that hazel-colored eyes are more likely to reflect the colors around them, such as the sky, a close surface, or what a person is wearing.

Basically, it’s like an optical illusion, if you’ll forgive the pun. Because of the color range and propensity for hazel colored yes to reflect different colored light surfaces, people often think they’re > > > changing color entirely.