Systems and methods may be provided for improving the visual performance of a human subject without the need to test the macular pigment concentration in the eye or eyes of the subject. The method may include identifying a subject likely to have an atypical ‘central dip’ macular pigment distribution; and administering an amount of a macular pigment-containing composition sufficient to improve the visual performance of the subject. Identifying a human subject, more likely than a subject selected at random from the general population, to have an atypical ‘central’ dip macular pigment distribution may include measuring at least one cognitive function of the subject; comparing the measured cognitive function with a pre-determined threshold; and, if the measured cognitive function is below the threshold, declaring the subject as being more likely to have an atypical ‘central dip’ macular pigment profile.