An electronic device may have a display such as a liquid crystal display. The display may include a layer of liquid crystal material interposed between a color filter layer and a thin-film transistor layer. The thin-film transistor layer may be provided with capacitive touch sensor electrodes. Wide metal lines on the thin-film transistor layer may be used to inhibit parasitic capacitances during touch sensor mode. The color filter layer may include a layer of black masking material that surrounds the active display area. A light-curable adhesive may used to attach the color filter layer to the thin-film transistor layer. Openings may be formed in the black masking material and in the metal lines on the thin-film transistor layer. The adhesive may be cured by applying ultraviolet light to the adhesive through the openings in the black masking material and through the openings in the metal lines.