15. The method of claim 14 , wherein: the validating a profile of first eye comprises: measuring profile metrics of the first eye; and determining whether the profile metrics of the first eye are valid; and the validating a profile of second eye comprises: measuring profile metrics of the second eye; and determining whether the profile metrics of the second eye are valid.
15. The method of claim 14 , wherein: the validating a profile of first eye comprises: measuring profile metrics of the first eye; and determining whether the profile metrics of the first eye are valid; and the validating a profile of second eye comprises: measuring profile metrics of the second eye; and determining whether the profile metrics of the second eye are valid. 16. The method of claim 15 , wherein the validating an amount of space between the first and second eyes comprises: measuring a spacing between the first and second eyes; and determining whether the spacing is within a valid range.