United States Naval Flight Surgeon's Manual: Third Edition 1991: Chapter 3: Vestibular Function Visual-Vestibular Interactions Relevant to Aviator Vision Naval Aerospace Medical Institute
Peer Review Status: Internally Peer Reviewed The Vestibulo-Ocular Reflex
The vestibulo-ocular reflex influences vision during natural movement much more than is generally appreciated, and it is capable of subtle and occasional profound influence on vision in aviation. Most physicians or physiologists think of nystagmus, an oculomotor pattern which occurs in certain unnatural motion profiles and in pathologic states, in relation to vestibular stimulation, but nystagmus is probably the least typical form of the vestibulo-ocular reflex in healthy individuals during natural movement. A more common oculomotor response consists of nearly smooth, sinusoidal eye oscillations that almost perfectly compensate for head oscillations that occur during walking, running, or simply shaking one's head, as in signifying "yes" or "no. "For example, in the latter situation as the head turns right, the eye turns left, thereby compensating for the head movement (cf. , Benson 1972). Gresty and Benson (in preparation) describe fairly high-frequency components (in the range 1 to 10 Hz) in angular oscillations of the head during whole-body movement and also in aircraft. It is important to note that the visual system is very poor at tracking Earth-fixed targets at these frequencies if it is unaided by the vestibulo-ocular reflex. Therefore, this reflex plays an important role in stabilizing vision relative to the Earth during many kinds of natural motion. The reader can demonstrate this to himself by holding his head | |
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