How is eye color determined?

Question

I remember learning that there are only two eye colors: brown and blue. Every other eye color is a result of these two combinations. Now I keep hearing about genes for every eye color. Can someone straighten this out for me? Are there just genes for brown and blue eyes, and every other tone (including green) comes from this, or what? Thanks!

Answer 1

All the various eye colours are results of interactions between a number of genes, there is not one gene for each colour.

There is only one colour of iris pigment -- brown. What the genes determine is how much, if any pigment is deposited in each of three layers of the iris, whether it is in clumps or evenly spread out and where the clumps are located. When light reflects off the layers, various colours are reflected. The light colours: blue, gray, green and light hazel are the result of little to no pigment in the top layer and some pigment in the lower two layers. The various shades of brown and dark hazel are the result of pigment in all layers.

Answer 2

Eye color is an inherited trait influenced by more than one gene. There are two major genes and other minor ones that account for the tremendous variation of human eye color. In humans, three genes associated with eye color are currently known: EYCL1, EYCL2, and EYCL3.These genes account for three phenotypic eye colors (brown, green, and blue) in humans. Eye color usually stabilizes when an infant is around 6 months old.

Answer 3

To expand on an earlier post, I don't think two people who don't have blue eyes but don't have brown eyes either can produce a child with brown eyes. My husband has gray/green eyes and mine are blue/gray and neither of our daughters have brown eyes. My older daughter's are deep gray and my younger daughter has light green eyes.

Answer 4

I know that two blue eyed ppl can't make a baby with brown eyes...