A system or method for measuring human ocular performance can be implemented using an eye sensor, a head orientation sensor, an electronic circuit and a display that presents one of virtual reality information, augmented reality information, or synthetic computer-generated 3-dimensional information. The device is configured for measuring saccades, pursuit tracking during visual pursuit, nystagmus, vergence, eyelid closure, or focused position of the eyes. The eye sensor comprises a video camera that senses vertical movement and horizontal movement of at least one eye. The head orientation sensor senses pitch and yaw in the range of frequencies between 0.01 Hertz and 15 Hertz. The system uses a Fourier transform to generate a vertical gain signal and a horizontal gain signal.