A head-mounted device may include a housing with a display that displays images that are viewable from an eye box. A light seal may be coupled the housing and may block outside light from reaching the eye box. The light seal may include a seamless tube of knit fabric that forms an outermost layer of the light seal. A light-blocking fabric may line the inner surface of the seamless tube of knit fabric. The light-blocking fabric may include a dark-colored weft knit layer facing the eye box, a light-colored weft knit layer facing and matching a color of the seamless tube of knit fabric, and a middle layer joining the light-colored weft knit layer and the dark-colored weft knit layer. The dark-colored weft knit layer may ensure sufficient opacity without being visible through the seamless tube of knit fabric.