Barbara Marquand is a staff writer at NerdWallet, a personal finance website. Email: bmarquand@nerdwallet.com. Twitter: @barbaramarquand.
The eye may change color due to alteration of genes in the cells of the iris. This is because of your DNA factors in the body. The gene alteration can cause the eye to change color from brown to green and vise verse. There is no any explanation to the cause of the genes behaving in these manner. Prolonged exposure to the sun might also be another cause that made my eyes to change the color.
It is very easy (especially in photographs) to change the perceived color of an object by changing the illumination. This is because the color of the light entering your eye from an object mixes up the color of the illumination and the color of the object, she wrote in a blog post Friday.