Abstract: A reflectometry instrument includes a light source, a spectrometer, and a first and second lens. The light source emits an illumination beam to the macula. The spectrometer measures a detection beam that is a portion of the illumination beam reflected from the eye and is indicative of the eye characteristics (e.g. macular pigment). The first and second lenses transmit the illumination beam to the macula and transmit the detection beam from the macula to the spectrometer. The instrument is used on an undilated pupil and minimizes unwanted reflections by at least one of the following: the first and second lenses include anti-reflection coatings; the illumination and detection beams pass through the first and second lenses at locations offset from their centers; and the illumination and the detection beams remain separated when passing through the first and second lenses. Zeaxanthin, lutein, and the total macular pigment levels are measured by the instrument.