1. A method for determining detection windows and window positions comprising: incrementally moving, by a processor, at least one detection window type over a region of interest to occupy different positions within the region of interest, the region of interest being an area of biometric data captured from a user; calculating a feature value for each position; creating a vector from the feature values; determining detection window type, size, and position combinations for calculating authentication feature values during authentication transactions; and determining eye openness measures during authentication transactions with the calculated authentication feature values.