text: I think you are referring to POLYGENIC inheritance.  This is the concept of multiple gene expression.  Very simply, Mendelian genetics usually suggests one gene pair or allele for any given phenotype or trait.  However, humans are just a smidge more complicated than a pea plant.  Because of this there is not just one gene pair or allele that dictates eye color.  In fact there are a myriad of genes contributing to human eye color.  That is where the term polygenic comes in.  A person inherits lots of genes coding for a lot of things.  In this particular case a person inherits a lot of genes (polygenic) for one particular thing (eye color).