A small grating is presented on the stimulation screen and is made to move at a slow velocity.
Visual acuity is estimated from the highest resolution of the grating that the subject is able to track.
Examples of the tests presented on the stimulator screen and corresponding to different visual acuities are presented hereby.
The equipment includes an eye tracker that analyzes the image of the baby’s face in real time. A reflective dot positioned over the forehead is used to determine the head movements. Eye gaze movements are measured from the position of the pupils relative to this reflective dot.
Even the youngest babies can follow a moving target provided that they are awake and that the stimulus movement is slow enough.
The results hereby have been obtained at different ages. The movement of the stimulus is indicated in green color whereas the eye tracking movement trace is shown in blue color.
This test can also provide information on delayed maturation of the eye movements and document eye movement disorders.