In dextroversion yoke muscle of right lateral rectus:
Ans. a. Left medial rectusRef: Kanskis Clinical Ophthalmology 8th Ed; Page No-732-33Yoke muscles (Contralateral synergists) are pair of muscles (one from each eye) which contract simultaneously during version movements.For example right lateral rectus and left medial rectus acts as yoke muscle for dextroversion movement.Others pairs of yoke muscles are:Right SR and left IO: DextroelevationRight IR and left SO: Dextro depressionRight IO and left SR: LevoelevationRight SO and left IR : Levodepression
Left medial rectus
Right superior oblique
Left lateral rectus
Right medial rectus
Ocular Motility