Quantification of Compensatory Eye Movements in Light and Darkness

Abstract

A broad frequency-band rotatory test has been used to quantify compensatory eye movements in 13 healthy subjects during light and darkness conditions. Eye movements were recorded by EOG. Head movements were recorded either by a potentiometer attached to the chair's axis of rotation or by an angular rate sensor attached to a bite-board. Gain and phase values between eye and head velocity were calculated. A systematic error in the higher frequency range is introduced in the results by assuming head movement equal to chair movement. Different instructions in the dark can alter the gain values at lower frequencies (up to 2 Hz) during sinusoidal stimulation. During pseudorandom stimulation no such differences can be obtained. During all test conditions with the rate sensor the gain values approach unity at about 3 Hz.