Gain
The "gain" of the VOR is defined as the change in the eye angle divided by the change in the head angle during the head turn. Ideally the gain of the rotational VOR is 1.0. The gain of the horizontal and vertical VOR is usually close to 1.0, but the gain of the torsional VOR (rotation around the line of sight) is generally low. The gain of the translational VOR has to be adjusted for distance, because of the geometry of motion parallax. When the head translates, the angular direction of near targets changes faster than the angular direction of far targets.
If the gain of the VOR is wrong (different from 1)—for example, if eye muscles are weak, or if a person puts on a new pair of eyeglasses—then head movement results in image motion on the retina, resulting in blurred vision. Under such conditions, motor learning adjusts the gain of the VOR to produce more accurate eye motion. This is what is referred to as VOR adaptation.
Ethanol consumption can disrupt the VOR, reducing dynamic visual acuity.
Read more about this topic: Vestibulo-ocular Reflex
Famous quotes containing the word gain:
“If you associate enough with older people who do enjoy their lives, who are not stored away in any golden ghettos, you will gain a sense of continuity and of the possibility for a full life.”
—Margaret Mead (1901–1978)
“When you sympathize with a married woman you either make two enemies or gain one wife and one friend.”
—H.L. (Henry Lewis)
“Today masses of black women in the U.S. refuse to acknowledge that they have much to gain by feminist struggle. They fear feminism. They have stood in place so long that they are afraid to move. They fear change. They fear losing what little they have.”
—bell hooks (b. c. 1955)