lens is one of main objects in optics; it was quite sufficiently elaborated as a subscene of 3D scenes in the realistic rendering. In this paper, we consider a development of a computer model of a lens to be a part of a computer model of a polarizing microscope (or polariscope), i. e., a model that takes into account polarization and coherency of light rays to provide computations of interference pictures. Lens geometry is a volume bounded by two transparent spherical surfaces and an opaque side surface (cylinder or cone); it is implemented as a single primitive of 3D scene along with other primitives like surfaces. An implemented lens model transforms an incident linear polarized light ray to outgoing rays with corrected intensity, polarization state and phase. Note that an effect of diffraction is not taken into account.