A chromatically dispersive lens configuration may be utilized in optical pens for chromatic range sensing. The lens configuration may include a negative power doublet lens and a positive power lens portion. The Abbe numbers of lenses included in the positive power lens portion may be between the Abbe numbers of the two portions of the doublet lens. The relationship between the Abbe numbers of the materials used in two portions of the doublet lens is generally opposite to their relationship as used in standard doublet lenses of similar geometry. The doublet lens may have a negative spherical aberration which effectively cancels a positive spherical aberration that arises in the positive lens portion. In one embodiment all of the lens elements in the lens configuration are spherical lenses. The lens configuration can be implemented with dimensions which fit a standard commercial optical pen, while providing improved range sensing performance.