Binocular Vision Concepts

Binocular Vision Essentials

• Proper coordination between the eyes and brain is essential for clear binocular vision

Eye Alignment

• Motor fusion describes the ability to align the eyes for proper binocular vision

Brain's Role

• In binocular vision, the brain combines two separate images

Neuroplasticity

• The ability of the brain and eyes to properly coordinate for binocular vision refers to neuroplasticity

Single Binocular Vision

• No partial decussation of optic nerve fibers is not a prerequisite for single binocular vision

Retinal Image Size

• Iseikonia refers to the equal size of retinal images

Iso-oxypia Defined

• Iso-oxypia is defined as equal best corrected visual acuity

Binocular Vision Advantage

• Enhanced depth perception

Binocular Visual Field

• 120 degrees is the binocular visual field range

Refractive Error Differences

• Anisometropia describes a significant difference in refractive errors between the two eyes

Temporal Crescent Size

• The typical size of the temporal crescent in the visual field is 90 degrees

Tertiary Eye Position

• Moving the eye to the right and slightly upward is classified as a tertiary position

Tertiary Position Defined

• Dextrosupra (rightward and upward) represents a tertiary position

Agonist Muscle Role

• The primary role of an agonist muscle is to move the eye in a specific direction

Synergist Muscle Role

• A synergist muscle helps the agonist muscle to produce the same movement

Benzene Ring Diagram

• The "benzene ring" diagram provides a cross-diagram of which muscle moves when the eye shifts in a given direction

Nasal Cornea Movement

• Adduction is the movement when the center of the cornea moves nasally (inward) along the vertical axis

Abduction Described

• Abduction of the eye is best described by movement about the vertical axis when the center of the cornea moves temporally (outward)

Upward Eye Movement

• The movement of the eye when the center of the cornea moves upward along the horizontal axis is termed elevation

Downward Eye Movement

• Depression refers to the downward movement of the center of the cornea along the horizontal axis

Wheel-Like Eye Rotation

• Incycloduction describes the wheellike rotation of the eye when the 12 o'clock point on the cornea moves inward (nasally)

Agonist Muscle for Movement

• Lateral Rectus, the agonist muscle of the right eye when the right eye is moves out and down

Yoke Muscle Movement

• Dextrosupraversion results if the yoke muscles are right superior rectus and left inferior oblique

Superior Visual Field Extent

• 60 degrees is the extent of the superior visual field

Overlapping Monocular Fields Extent

• The extent of the overlapping monocular fields is 120

Eyeball Halves

• The transverse plane divides the eyeball into anterior and posterior halves

Torsional Movement

• The vertical axis is responsible for torsional movement

Eyeball Portions

• The horizontal plane divides the eyeball into superior and inferior halves

Antero-Posterior Axis

• The optic axis is also referred to as the antero-posterior axis

Outward Eye Movement

• Abduction occurs when one eye moves outward

Equatorial Plane Function

• The equatorial plane divides the eye into anterior and posterior halves

Bilateral Eye Movement

• Levoversion describes the movement of both eyes to the left

Transverse Axis and Rotation

• The transverse axis passes through the center of rotation and is perpendicular to the optic axis

Fixation Defined

• Fixation is the act of directing the eye towards the object of regard

Vertical Eye Movements

• The transverse axis is the axis responsible for vertical eye movements such as supraduction and infraduction

Inward Eye Movement

• Adduction occurs when one eye moves inward towards the nose

Dextrosupaversion Defined

• Dextrosupaversion describes both eyes moving to the right and upward

Optic Axis Orientation

• The transverse axis passes through the center of rotation and lies at a right angle to the optic axis

Median Plane Division

• The median plane divides the eye into left and right halves

Vertical Axis Control

• Torsional movement is controlled by the vertical axis (Z-axis)