In contrast to normal light, polarized light is in a single plane of the light waves. Polarized light reveals anisotropic objects, whose observable properties depend on the direction of light, "in a new light": crystals, but also animal hairs, feathers, muscles, nerve fibers and vegetable cell walls, which have a preferred direction of its bimolecular, show structures now, which were hidden in the normal bright field image. Images made by polarized light are often characterized by a fantastic coloring. Polarization microscopes are used particularly in mineralogy, geology, biology and medicine.

In order to change the object's direction in a controlled way, the Science MPO 401 has a round, center-adjustable and full rotatable object stage with degree scale. The illumination is provided by halogen bulb lamp (20 W) with dimmer, the field diaphragm (used to achieve the Köhler illumination), the 360° rotatable polarizer (for the production of polarized light), and centering implements for the objectives and the analyzer attachment (for the analysis of the polarized light). The analyzer attachment is meant for receiving the 360° rotatable analyzer and optional available slips (Bertrand lens for conoscopy; quartz wedge, » plate and »/4 plate used in order to get special colour effects). The wide field eyepieces (WF10x), which are also optional available, are placed at the trinocular head with an inclination of 30°. They have eye relief adjustment as well as dioptre adjustment. The images shown by them are bright, true colored, sharp and rich in details. Apart from the slips and eyepieces, which were mentioned above, the accessories of the MPO 401 contain a dividing eyepiece (WF10x), the Abbe condenser with iris diaphragm, special polarization objectives (4x, 10x, 40x retractable, 100x-oil retractable), filters (blue, ground glass) and immersion oil.