The reflection, absorption, and transmission of light at visible and near-infrared wavelengths by snow and ice covers is important for a number of geophysical problems. The focus of this paper is on the reflection and transmission of light by spatially inhomogeneous and temporally varying sea ice covers. This is investigated using a two-stream, multilayer radiative transfer model in the wavelength region from 400 to 1000 nm. The model is computationally simple and utilizes the available experimental data on the optical properties of sea ice. The ice cover is characterized as a layered medium composed of selections from nine distinct snow and ice types. Three case studies are presented illustrating values of spectral albedo, transmittance, and transmitted photosynthetically active radiation (PAR) for (1) a spatially inhomogeneous ice cover, (2) a uniform ice cover as it undergoes a melt cycle, and (3) a temporally changing spatially variable ice cover. Results indicate that small-scale horizontal variations in snow depth and ice thickness can cause light transmission to change over 3 orders of magnitude. Dramatic changes in light reflection and transmission are predicted in the early part of the melt season as the ice cover evolves from an opaque, snow-covered medium to translucent bare or ponded ice.