An electronic device may include a lenticular display. The lenticular display may have a lenticular lens film formed over an array of pixels. The lenticular lenses may be configured to enable stereoscopic viewing of the display such that a viewer perceives three-dimensional images. To mitigate jaggedness in a curved edge of the active area, control circuitry may modify input pixel data for the display using dimming factors. Each brightness value of the pixel data may be multiplied by a corresponding dimming factor such that the curved edge has a smooth appearance. Each physical pixel in the display may have an associated perceived pixel that is based on an appearance of that physical pixel through the lenticular lens film. The perceived pixel may have a different footprint than its corresponding physical pixel. The dimming factors for boundary smoothing in the curved edges may be based on the perceived pixels.