A method of forming an array of selectively shaped optical elements on a substrate, the method including the steps of providing the substrate, the substrate having an optical layer placed thereon; placing a layer of particles on the optical layer; performing an etching cycle. The cycle includes the steps of: etching the layer of particles, using a first etching process so as to reduce the size of the particles within the layer, then; simultaneously etching the optical layer and the layer of particles, using a second etching process, the further reducing particles forming a mask over areas of the optical layer to create discrete optical elements from the optical layer.