A method of metrology target design is described. The apparatus comprises an optical stimulator configured to optically stimulate a nerve area affecting a person’s balance, and a control module coupled to the optical stimulator, the control module being configured to control the optical stimulator. A binder in the front row of the binder cartridge is moved by a binder lateral movement mechanism along the crank-shaped guide groove in the lateral direction and is separated from the other binders. Within a vertical scanning period, a working voltage and a black voltage are sequentially applied to a plurality of pixels on a LCD. A semiconductor structure formed thereby is also provided.