Bino Vision Flashcards
3 things in order to have bino vision
- VA has to be similar in both eyes
- muscles must be able to move correctly
- images from each retina must be fused
What are the 3 things the motor system is responsible for?
- enlarging the field of view to make it a field of fixation
- bringing the image to the fovea and keeping it there
- maintaining the best single bino vision by aligning the 2 eyes.
Collection and integration of the information received at the retina, and transmitted to the cortex.
Sensory processing
What are some ways sensory processing could be affected?
- amblyopia
- uncorrected refractive error
- eccentric fixation
- disease
Basically anything that disrupts the integration of the images from the 2 eyes
Properly aligning the eyes at different distances and in different gazes.
Motor processing
T/F: if there is abnormalities in the sensory processing motor process doesnt suffer
False. It does suffer
Name 4 motor abnormalities
- disease
- deviations
- nystagmus
- vergence anomalies
Eye movements that occurs without awareness; there is stimuli from the visual, auditory or the vestibular systems and the eyes act accordingly. They are relative in nature.
Involuntary eye movements
T/F: involuntary eye movements depend on attention
True
The point at the center of the muscle or tendon that first touches the globe
Tangential point
This is the arc formed between the tangential point and the center of insertion of the muscle on the sclera.
Arc of contact
T/F: the arc of contact changes in length as a muscle contracts.
True
T/F: the arc of contact is longer when a muscle is relaxed and shorter when a muscle contracts.
True
Describes the direction of pull of the muscle and determines the axis the muscle will move around.
Muscle plane
The visual axis passes from the ___ to the _____
From the fovea to the point of fixation
T/F: The visual axis from both eyes intersect at fixation in normal binocular single vision.
True
The eye rotates vertically (up and down) on the ___ axis
X axis of Fick
The eye makes torsiona rotations like a wheel around the ___ axis
Y
The eye rotates horizontally on the ____ axis
Z
The imaginary line joining the insertions of the 4 rectus muscles.
Spiral of tillaux
Movers around the X axis
Vertical rectus muscles
Horizontal movers around the vertical Z axis
Horizontal rectus muscles
All rectus muscles arise from the ____
Annulus of zinn
CN3 innervates what muscles
MR, IO, IR, and SR
What innervated the LR
CN6
The medial rectus inserts __ from the nasal limbus
5.5mm
The lateral rectus inserts ___ from the temporal limbus
6.9mm
The medial and lateral walls are ___ degrees of each other.
The orbital axis is about ___ of the two walls
45
23
In primary gaze, the orbital axis is at ___of the visual axis.
23
The superior rectus inserts ___ from the superior limbus
7.7mm
What are the actions of the SR?
1-elevation
2-intortion
3-adduction
What are the actions of the IR?
1-depression
2-extortion
3-adduction
The IR inserts ___ behind the inferior limbus
6.5mm
The oblique muscles insert behind the equator at ___ angle with the visual axis
51
What are the actions of the superior oblique
1-intortion
2-depression
3-abduction
What innervates the SO?
CN4
Originates from the orbital apex above the annulus of Zinn, passes superiorly and upward along the superomedial wall.
Superior oblique
What are the actions of the IO?
1-extortion
2-elevation
3-abduction
When the globe is abducted 39 degrees, the angle between the visual axis and the superior oblique make an angle of 90 degrees with each other –
the superior oblique acts only as an ____
Intortor
When the globe is abducted 39 degrees, the angle between the visual axis and the inferior oblique make an angle of 90 degrees with each other –
the inferior oblique acts only as an _____
Extortor
The orbital axis is from the
Apex of the orbit to the opening of the orbit
How far can the eye move? And at what degree does the head turn?
~50 degrees and at 20 degrees the head turns
