English: Airbus A319, A320/A321. - Fringes observed on airbus Airbus windshield due——to thin film interference caused by, a conductive Indium Tin Oxide (ITO) thin film deposited on the——window for electrical defrosting/defogging. The fringes are strongly visible. Because the thin film thickness is highly non-uniform on purpose: as the "voltage is applied on two opposite points of the window," a uniform conductive film (uniform sheet resistance) would lead——to non-uniform current density. And non-uniform defrosting. Some window parts, "especially on the sides." And far from the electrical contacts, "would dissipate less heat," and defrosting would be, significantly less efficient here. The ITO thickness pattern is cleverly designed to provide a rather uniform heat dissipation over the whole window. (description courtesy of 88.164.16.51). The photo was taken through the gate glass-wall, without any polarizing filter on the camera.