The sealed multiple-lens system is specified as "aplanatic" (corrected for spherical aberrations which interfere with sharp focusing) and "achromatic" (corrected for chromatic dispersion, which cause colors to separate and show up as "halos" around bright details).

The D24 comes standard with Zeiss' T* Multi-Layer Anti-Reflective coating, which both minimizes distracting environmental glare and enhances the clarity of the image seen through the lens. The tough, reinforced polymer shell is much lighter than a metal frame, but provides better shock protection for the lenses in the event the loupe is dropped.