Microscopists have continually developed new techniques for enhancing specimen contrast since Zacharius first built the first compound light microscope around 1595. His simple two lens microscope became the basis for the evolution of light microscopes until 1828. That date is when the first polarizing light microscope was invented by Nichols. Since then, it has served as the building block for most research microscopes that are fitted for accessories made to enhance contrast or measure specific optical properties.
Julius Rheinberg devised a simple contrast enhancement method in 1896. He published his findings in the journal of the Royal Microscopical Society for the benefit of others. Today, Rheinberg illumination (RHI) has given way to phase contrast, differential interference contrast, confocal, laser microscopy, scanning probe and atomic force microscopy. The latter four are very recent technological advances.