What part of the human eye defines the eye color?

Green eyes are the only ones that change colour, they can go from green to blue then greyish , it can depend on the colours you’re wearing such as purple emphasis green, crying or having a sun tan can bring out the blue

Mirza, people with blue eyes see better their light colored eyes let in more light

slomogeo, Your generalised statement is faulty. In bright light - like outdoors in much of Africa - brown and black eyes are superior to blue in, for example, being able to differentiate the finest details of the "spoor" or "tracks" left on the ground by people or animals. Trackers in the South Africanand Rhodesian defence forces were never blue-eyed.

rcc, u still have 2 brown eyes but 1 u can't see, lol

Those were some eye opening facts!

There are many eye colors..

Player #46835611, neither is mine!

Player #28825483, Mood and health can also be factors.

Player #28825483, I have green eyes and if the color fluctuates I would think it would depend if I were in bright light or not. Unsure.

yeah it's Ires.. it's really great knowledge ♥