EYE MOVEMENTS Flashcards
What is the Vestibular eye movement?
This hold the images steady on the retina during brief head rotations or translations.
What is the visual fixation eye movement ?
Holds image of a stationary object on the fovea (minimises ocular drift)
What is optokinetic eye movements?
Holds the images steady on the retina during sustained head rotations
What are smooth pursuit (version) eye movements?
Holds the image of a small moving target on the fovea
What is Nystagmus quick phases eye movements?
Reset the eyes during prolonged rotation and direct gaze towards the oncoming scene. Brings eyes back to primary position
What are saccades (versions) eye movements?
It is a rapid conjugate eye movement that shifts the center of gaze from one part of the visual field to another
Brings images of objects of interest onto the fovea
What is vergence eye movements?
Moves the eyes in the opposite directions so that images of a single object are placed or held on the fovea of both eyes simultaneously.
What is vergence eye movements?
Moves the eyes in the opposite directions so that images of a single object are placed or held on the fovea of both eyes simultaneously.
What are torsions?
Torsional movements that rotate
e.g. to keep the horizon horizontal during head tilt
What is intorsion?
Intorsion is the rotation of the eye nasally
What is extortion?
Rotation of the eye temporally
What is the Hering’s Law of Equal Innervation?
It states that equal and simultaneous innervation occurs for yoke muscles (paired muscles) during any conjugate (same direction) eye movements.
Sherrington’s Law of Reciprocal Innervation?
This law states that increased innervation to an extraocular muscle is accompanied by a reciprocal decrease in innervation to its antagonist
e.g. innervation of the right superior rectus muscle results in inhibition of the right inferior rectus muscle.
What is the visually guided saccade?
Endogenous direction of gaze to an object of interest
What is the reflexive saccade?
Triggered exogenously by the appearance or disappearance of a peripheral or fixation stimulus
