We present a multispectral digital colposcope (MDC) to measure multispectral autofluorescence and reflectance images of the cervix by using an inexpensive color CCD camera. The diagnostic ability of the MDC was evaluated by application of MDC spectral response to fluorescence and reflectance spectra measured from a large clinical trial. High diagnostic performance was achieved by use of only two excitation wavelengths: 330 and 440 nm. Good quality autofluorescence images of the human cervix were acquired in vivo with the MDC. Automated diagnostic algorithms correctly identified CIN (cervical intraepithelial neoplasia) lesions from MDC fluorescence images. The MDC has the potential to provide a costeffective alternative to standard colposcopy and better direction of biopsies.

Ultrabright light emitting diodes (LEDs) are a new light source for visual psychophysics and microscopy. The new LEDs are intended primarily for room and exterior illumination, and the manufacturers' specifications are adequate for that. However, we use them as light sources in situations where a more complete characterization may be useful. For one set of LEDs we have measured the radiometric intensity and its distribution in space and wavelength, and we have tested for interactions of these variables and their dependence on driver configuration. We describe techniques for making these measurements and give a link to a simple calculator for converting among radiometric and photometric measures, as well as an evaluation of the safety considerations these very bright sources demand.

Color matches made with a Nagel anomaloscope are used in the differentiation of color vision deficiencies. When these color matches are made over a wide range of retinal illuminances, the changes in the color match provide information about the regeneration kinetics and the absorption spectra of the middle- and long-wavelength cone photopigments. These steady-state color matches vary with a variety of conditions, and may have value in screening for eye disease. Recently, high-brightness LEDs have become available that allowed us to construct a LED-based, high-brightness anomaloscope. We used inexpensive, low-energy components to replicate an earlier instrument, getting a maximum retinal illuminance over 5.6 log Trolands.