The invention relates to a process for manufacturing an optical article having antireflection or reflective properties comprising a substrate having at least one main surface, which process comprises: a step of depositing a sublayer on a main surface of the substrate; a step of treating the sublayer by ion bombardment; and a step of depositing, on said sublayer, a multilayer stack comprising at least one layer having a high refractive index and at least one layer having a low refractive index. According to a preferred embodiment, the sublayer is deposited in a vacuum chamber with a gas introduced into the chamber during the deposition step.