Re: What is the probability of two blue eyed people having a brown eyed child?

Jill,

You have a very good question.  However, it is not very easy to answer.  
To date there are three genes know to control eye color.  Each gene does 
not conrol a specific color.  For example, the two genes on chromosome 
fifteen control different color.  One controls blue and brown while the 
other controls central brown.  The third gene on chromosome 19 controls 
blue and green eye color.

Therefore it is very difficult to give a specific percentage unless there 
has been a study of individuals and their offspring.  However, this study 
must only look at phenotypes (expressed characteristics) instead of 
genotypes.

I have attached a website that shows some complexities to answering your 
question.

Sincerely,

Mike
 http://www.seps.org/cvoracle/faq/eyecolor.html