Comment on "Precision refractive index measurements of air, N2, O2, Ar, and CO2 with a frequency comb".

The measured oxygen refractive index formulas are still not sufficient for precise metrological applications. Thus, a new dispersion formula for the molecular oxygen refractive index at standard conditions is derived. The agreement of the standard air refractive index obtained from indices of its components with recent dry air refractive index formulas is within a few billionths.