Eye colour

It's an amazing thing, eye colour - i found this on the net, which is quite interesting:

In a blue eye there is not much melanin in the anterior border layer. The light passes into the stroma where the collagen fibres scatter the light back as blue. In a green eye (or a hazel one) there is a variable level of melanin, so that some of the light is absorbed by the melanin and some is scattered by the collagen. The brown layer looks yellow as it is thinner, and so the yellow and blue mix to make green.

Well there you go. And this net excerpt explains why brown eyes are so dominant and why green are so unusual:

Your eye colour is determined by your genes. When you are made two sex cells join: one from your mother and one from your father. These cells to some extent determine what you will look like.Each gene is made up of two alleles: these can be either dominant or recessive (a dominant allele dominates a recessive allele). Eye colour will be determined by your parents for example: if both your parents have brown eyes and their alleles are the same (homozygous brown) or (BB) the child will definitely have brown eyes.It is however possible for a person with brown eyes to have a blue eyed allele. Blue is recessive: therefore if you have 1 blue allele and one brown allele you will have brown eyes. Your gene will be (Bb) B= brown and b=blue. If two people with this gene (Bb) have a child there is a 1 in 4 chance that it will have blue eyes. Because the blue allele is recessive you will only have blue eyes if your gene is (bb). Therefore two blue eyed people will definitely have a blue eyed baby. Green is the most recessive eye colour this means that both blue and brown is dominant over it.

It also goes on to say that most babies have blue eyes - but these can and often do change. Apparently a baby's eye colour should stabilise around the 6 mth mark.