Having blue eyes is a mutation, so should people with blue eyes be called mutants too? Its literally a birth deformity.
That's not a birth defect.
A birth defect happens during development of the love cells or during pregnancy, such as downs syndrome, thalidomide babies, or cleft lips.
Blue Eyes are a result of a mutated gene which mutated at least 7000 years ago, possibly further.
Every person born with blue eyes was always going to have blue eyes, because the love cells that formed them already contained the gene for blue eyes.
There is no mutation occuring in the love cells or embryo that caused blue eyes in people born with them today.