The field of Genetics has developed a lot. Here is a good example of this. If you wish to know the eye color your child will have, you can calculate it with the help of this eye calculator
This software provides a rough estimate of your childs eye color based on the two generations of eye colors in your family. The calculations are based on two genes that determines any persons eye colour - bey2 and gey.
It is said that "you have two copies of the bey2 gene and two copies of the gey gene, one from each parent”. You can choose from three different eye colors - green, brown and blue eyes. Based on these data the software does some permutations and combinations and then gets you the possible eye colour based on the probability percentages.