Flashcards in 9- Abnormal And Normal Binocular Vision Deck (64):
What is normal binocular vision?
Both eyes used simultaneously for both retinal images of a target contribute to the final perception
Binocular vision requires the working together of what 2 systems?
Motor and sensory
What is the sensorimotor unit of the eye?
Light hits the retina, producing chemical and physical changes at the photoreceptors, impulses are transmitted to the CNA and we become aware of visual stimulation
What can affect sensory processing?
Any condition that prevents the integrator of the images from the 2 eyes
Ex. Amblyopia, uncorrected refractive error, eccentric fixation, disease
What is the motor process involved in?
Properly aligning the eyes at different distances and in difference gazes
T/F abnormalities n the sensory processing affects the motor?
What is included in teh spectrum of motor abnormalities
Voluntary eye movements
You willed the eye movement
Involuntary eye movement
Occurs without awareness
What is a saccadic movement?
When the image over quickly across the retina with no apparent movement
What is the action of a muscle due to?
Direction of its pull around the axes
Primary action of a muscle is
It's major effect on teh position of the eye when the muscle contracts while the head is in primary position
Secondary and tertiary actions of a muscle are
Additional effect a muscle has on the position of the eye
The eye can move about ____ degrees but after ____ degrees the head turns
Point at the cente of the muscle or tenon that first touches the globe
Arc of contact
Formed between the tangential point and the center of insertion of the muscle on the sclera
(Changes in length as the muscle contracts)
Direction of pull of the muscle and determines the axis the muscle will move around
Visual axis passes from ____ to ___
Fovea to point of fixation
T/F the visual axis of both eyes intersect at fixation?
The globe rotates on this axes
Axes of Fick
The X axis has this movement
Vertical (up and down)
The y axis makes this movement
Torsional rotations like a wheel
The z axis does this movement
Horizontal (left and right)
What are 4 rectus muscles
What are the 2 oblique muscles
What is the imaginary line that joins the rectus muscles
Spiral of tillaux
What is the spiral of tillaux important for?
The medial rectus is this far from the limbus
The superior rectus is this far from the limbus
The lateral rectus is this far from the limbus
The inferior rectus is this far from the limbus
All rectus muscels arise from this
Annulus of Zinn
Medial rectus allows this motion
Moves eye to nose
MR is innervated by this
LR allows this movement
Moves eye away from nose
LR is innervated by
The medial and lateral walls of the eye are at what angle to each other?
The orbital axis is what angle of the medial and lateral walls
Where does the orbital axis run from
The apex to the opening of the orbit
N primary gaze with the angle of the orbital axis
What is the primary action of the SR
What is the secondary action of the SR
What is the tertiary action of the SR
SR is innervated by
The SR forms this angle with the visual axis
When the glob is abducted 23 degrees the SR is only a(n) _______
When the glob is adducted 67 degrees the SR has only this action
The primary action of the IR is
Move eye down
The secondary action of the IR is
IR is innervated by
The IR forms this angle with the visual axis
When the globe is abducted 23 degrees the IR acts only as a
When the globe is adducted 67 degrees the IR is only a
The 2 oblique muscles insert behind the equator at this angle with the visual axis
What is the primary action of the SO
What is the secondary action of the SO
What is the tertiary action of the SO
SO is innervated by
The SO passes through this
The primary action of the IO is
The secondary action of the IO is
The tertiary action of the IO is
IO is innervated by