So far, detailed stellar population studies, based on the absorption line strengths have been concentrated mainly in the optical spectral range. In this work, we supplement spectral indices of the Lick system in the optical with additional indices in the near-infrared (NIR). We optimised the definition of the indices to be sensitive to the main stellar population parameters, i.e. age, metallicity and stellar initial mass function (IMF) and fully characterized them with velocity dispersion, signal-to-noise ratio and elemental abundance ratio effects.