Switchable window element having a dark state and a bright state and a layer structure comprising a switchable layer, two polarizers and two optical retarders, wherein a first polarizer and a first optical retarder are arranged in an optical path prior to the switchable layer and a second polarizer and a second optical retarder are arranged in the optical path after the switchable layer, wherein the switchable layer is a vertically aligned liquid crystal layer comprising a liquid crystalline medium, wherein the product of the thickness d of the switchable layer and the optical anisotropy Δn of the liquid crystalline medium is in the range of from 0.05 μm to 3.0 μm and the liquid crystalline medium has a clearing point of at least 70°C, wherein the layer structure comprises in this order a first polarizer layer as first polarizer, a first retardation element as first optical retarder, a first electrode layer, a first alignment layer, the switchable layer, a second alignment layer, a second electrode layer, a second retardation element as second optical retarder, and a second polarizer layer as second polarizer, wherein the first retardation element and the second retardation element are layer structures comprising an optically isotropic substrate and a retardation layer (32, 38). wherein the switchable window comprises at least one further substrate and at least one interlayer, wherein the at least one further substrate is connected to the first polarizer layer and/or second polarizer layer by means of the at least one interlayer, wherein in the dark state the transmission of visible light through the switchable window element is less than 2%, wherein the transmission of visible light is measured in accordance with EN 410:2011-04, and wherein the switchable window element is curved in space along two directions. wherein the switchable layer is a vertically aligned liquid crystal layer comprising a liquid crystalline medium, wherein the product of the thickness d of the switchable layer and the optical anisotropy Δn of the liquid crystalline medium is in the range of from 0.05 μm to 3.0 μm and the liquid crystalline medium has a clearing point of at least 70°C, wherein the layer structure comprises in this order a first polarizer layer as first polarizer, a first retardation element as first optical retarder, a first electrode layer, a first alignment layer, the switchable layer, a second alignment layer, a second electrode layer, a second retardation element as second optical retarder, and a second polarizer layer as second polarizer, wherein the first retardation element and the second retardation element are layer structures comprising an optically isotropic substrate and a retardation layer (32, 38). wherein the switchable window comprises at least one further substrate and at least one interlayer, wherein the at least one further substrate is connected to the first polarizer layer and/or second polarizer layer by means of the at least one interlayer, wherein in the dark state the transmission of visible light through the switchable window element is less than 2%, wherein the transmission of visible light is measured in accordance with EN 410:2011-04, and wherein the switchable window element is curved in space along two directions.