Czerny continued the research of the infrared spectral range from (under Rubens) to 300 microns wavelength up to about 1400 microns by developing new measuring methods and apparatuses begun by his teacher Rubens. During his time in Berlin, he was also known for his work with A. F. Turner and the doctoral student V. Plettig on astigmatism in mirror spectrometers. He dealt with thermal limits of measurement (which was by no means common knowledge in the 1920s), techniques of infrared photography (evaporography) and, in World War II, sensitivity of the eye to high-intensity infrared (important in why Allied bomber crews apparently used the infrared - could detect anti-aircraft headlights). The insensitivity to infrared is an adaptation of the visual system to the thermal radiation of one's own blood, as Czerny showed in 1949. In 1972 he published a paper on changes in the optics and vision of the eye after cataract surgery (e.g. greater sensitivity in the ultraviolet). After World War II he published on lightweight bolometers, the beginnings of the later alternating light process. He also dealt with application problems in the glass industry (heat conduction by radiation).