Which measurement describes a material’s ability to disperse white light into colors?

The ABBE number is a measurement that specifically indicates a material's ability to disperse white light into its constituent colors, which is known as chromatic dispersion. This value quantifies how much light is refracted when passing through a material, primarily focusing on the wavelengths of light. A higher ABBE number signifies a lower tendency to disperse light into different colors, indicating that the material will produce less chromatic aberration when used in lenses.

In contrast, the refractive index measures how much light is bent when entering a material but does not account for the dispersion of colors. Optical power refers to the focusing ability of a lens based on its curvature and refractive index but also does not describe dispersion. Light transmission measures how much light passes through a material, which is important for assessing clarity and darkness in lenses, but does not relate directly to the separation of colors. Thus, the ABBE number is the most relevant measurement for understanding how a material disperses white light into colors.