A method and an apparatus for demonstrating optical properties of a lens for spectacle glasses are disclosed. A demonstrational tool exposes a spectacle lens or a pair of spectacle glasses to polarized light to demonstrate how the removal of polarized, reflected light from a display reduces glare. Further, the demonstrational tool exposes a phototrope lens or a pair of spectacle glasses with phototrope lenses to UV- or HEV-light to demonstrate the reversible self-tinting of the phototrope lenses.