Abstract: A method and apparatus for measuring the absorption characteristics of complex lenses to light from a selected band of wavelengths, preferably wavelengths in the ultraviolet range, is disclosed. Light from an incandescent light source is passed through a tunable interference filter, which passes light having only wavelengths from the selected band of wavelengths, and is directed toward a first side of a lens to be tested. An integrating light detector, preferably a selenium solar cell is placed in close proximity to the second side of the lens to be tested, and senses substantially the total amount of light flux passing through the lens, regardless of the lens' complexity and light diverging characteristics. The output of the detector is fed through amplifier circuitry to a suitable indicating meter. A light impervious housing structure may be provided to prevent ambient light from impinging on the detector. The device utilizes inexpensive elements, is very accurate, may be hand held, and is simple to use.