Percival criterion

criterion, Percival

Rule proposed by Percival to establish whether a patient is going to experience discomfort in binocular vision. It states that if Donders' line (or demand line) lies within the zone of comfort, which is the middle third of the total range of relative convergence (to the blur points), Percival's criterion of comfortable binocular vision is fulfilled. If it is not, appropriate prisms, spherical lenses or visual training can be used to shift the demand point within the zone of comfort. In this criterion, no reference is made to the actual phoria of the subject and for this reason it has been criticized by several authors. Syn. middle third technique. See relative convergence; binocular vision single zone of clear.

单词	percival criterion
释义	Percival criterion criterion, Percival Rule proposed by Percival to establish whether a patient is going to experience discomfort in binocular vision. It states that if Donders' line (or demand line) lies within the zone of comfort, which is the middle third of the total range of relative convergence (to the blur points), Percival's criterion of comfortable binocular vision is fulfilled. If it is not, appropriate prisms, spherical lenses or visual training can be used to shift the demand point within the zone of comfort. In this criterion, no reference is made to the actual phoria of the subject and for this reason it has been criticized by several authors. Syn. middle third technique. See relative convergence; binocular vision single zone of clear.
随便看	space aliens space alliance technology outreach program space allocation space alternating generalized expectation space-alternating generalized expectation maximization algorithm space analysis resource portal space and astronautics orientation course space and data tracking network space and earth sciences advisory committee space and electronic warfare space and electronic warfare simulator space and electronic warfare tactical work station space and ground based observations space and intelligence systems space and life sciences directorate space and missile defense technical center space and missile systems center space and missile test & evaluation command space and missile test organization space and naval warfare command space and naval warfare systems center space and power space and the universe space and time space applications advisory committee