We have investigated planar LC cells with striped electrodes and two types of surface alignment of the director. Their optical properties are studied by means of polarizing microscopy, and a simple model is presented to determine the twist and tilt deformation of the director field. The optical patterns are simulated by computing the transmission function of the cell with model director deformations using the 4 x 4 matrix formalism. Depending on the director alignment at the surfaces, different types of inversion walls have been observed. They form structures of a characteristic geometry influencing the optical performance of LC devices. LC parameters may be calculated from the geometrical patterns of the observed defects. Any further attempt to calculate the exact static two-dimensionally (2D) deformed director fields in structured NLC cells ought to be checked by its consistency with the experimental effects reported here.