A head-mounted display device includes a modular frame assembly including one or more different components. Each of the different components may be selected from a component set including at least two or more differently-sized versions of each different component. The head-mounted display device also includes a modular see-through display sub-assembly including one or more mountings for selectably coupling the modular see-through display sub-assembly to the modular frame assembly. The modular see-through display sub-assembly may be configured to couple to any combination of differently-sized versions of different components of the modular frame assembly.