Embodiments of the present invention provide light diffusion into edge lines of a modular display, and thus provide a modular display that is capable of displaying a single, continuous image without visible edge lines between individual display modules. One display module includes a multitude of pixels that contain red, green, blue, and white light sources. The replacement of an edge line blocking dam with the light diffusion edge line of the individual display module can provide a single, continuous image to be displayed thereon without visible, image-quality-reducing edge lines. With various heights of the buffer layer, the light can concentrate on the edge line in modular display. The individual display modules can be light emitting diode (LED), organic LED (OLED), UV LED, RGB LED, Phosphor-based LED, Quantum dot LED, or displays based upon a combination thereof. Furthermore, the variable height buffer layer allows for a modular display image in 2-dimensional or 3-dimensional formats.