Blending of sight to form single percept

Proper coordination of eyes and brain

Eyes are not associated with each other; act as two different organs

First sign of the development of fixation appears when the eyes follow light

Eyes follow large objects

Foveas are fully formed

Eyes are expected to be straight

Fixates at an object for 1 - 2 minutes

VA 20/70

Fusional mechanism becomes fully developed

VA 20/20

Light passing through a prism is bent towards the _

Eye looking through a prism is displaced on the _

Object viewed through a prism is displaced towards the _

Movement of one eye only

Movement of the vertical corneal meridian of one eye outward

Synchronous and symmetric movement of both eyes in the same direction

Supraversion other name:

Infraversion other name:

Synchronous and symmetric movement of both eyes in the opposite direction

OD: Up

OS: down

OD: Down

OS: Up

vertical meridians of both eyes rotate inward

vertical meridians of both eyes rotate outward

Position which the eyes assume when with the head erect, point straight ahead on the horizon is fixed upon

Position in which the eyes assume when the lateral or vertical movements are involved

Position in which the eyes assume when it moves in a direction which is a combination of both lateral or vertical movements

All originates at the annulus of zinn except?

Insertion from the limbus:

MR:

LR:

SR:

IR:

Strongest, heaviest, broadest EOM

Points of connections of all recti muscles

Primary muscle

Helping muscle

Corresponding muscle of the two eyes that affect movement of both eyes into a specific gaze

Dextroversion

Agonist

Divergence

Antagonist

Levocycloversion

(Head tilting to the right)

Synergist

Dextrocycloversion

(Head tilting to the left)

Yoke muscle

Imaginary line where movements of the eye takes place

22 mm, superior inferior line passing through COR

22 mm, Line passing through the COR of the eyeball and at right angle to optic axis

Horizontal line from vertex of the cornea to posterior pole of the eye

Other name of the Following:

Optic Axis:

Transverse Axis:

Vertical Axis:

Y axis:

X axis:

Z axis:

Divides the eyeball

Lie to the optic axis and transverse axis

Lie the transverse axis and vertical axis

Lie the optic axis and vertical axis

Divides eyeball to right and left hemispheres

Divides eyeball to upper and lower portion

Divides eyeball to anterior and posterior halves

Line drawn from the object of regard to the fovea and passing through the nodal point

Line from the center of entrance pupil and passes through the center of curvature of the cornea

Line perpendicular to the cornea and passing through the center of the entrance pupil of the eye

An imaginary straight line passing through the midpoint of the cornea (anterior pole) and the midpoint of the retina (posterior pole)

Angle formed by the intersection of the pupillary axis and the line of sight

Angle formed by the intersection of the optic axis and the line of sight at the COR

Angle formed by the visual and optic axes at the nodal point

Line connecting the COR of both eyes

Plane which includes both the object of regard and baseline

Line in the primary position of the plane of regard which bisects the baseline

Plane tangent to the chin and the two super-ciliary ridges

Retinal elements of the two eyes that share a common subjective visual direction

Both foveas have a common visual direction and the retinal elements nasal to the fovea in one eye correspond to the retinal elements temporal to the fovea of the other eye

Fovea of one eye has a common visual direction with an extrafoveal area in the other eye

a theoretical circle passing through the fixation point and nodal points of the two eyes

A zone infront or behind the horopter in which an object may lie and still be seen as a single image despite stimulating non corresponding elements

Diplopia occurring in normal binocular vision for non fixated objects whose images stimulate disparate points on the retina outside of the pajum’s area

Objects beyond the point of binocular fixation

Objects nearer than the points of binocular fixation

States that fusion operates upon a psychological and cerebral level

Theory of replacement or theory of retinal rivalry

Based upon alternate shifting mosaic patterns from each ocular image

Maintains that single image is merely a projection of two identical images to the same perceptual position and that two ocular images are perceived as one because of their community location

Degrees of fusion:

Grade 1:

Grade 2:

Grade 3:

Depends on the mechanical properties of the orbital structures and only occurs when the muscles are not innervated, as in anesthesia or death

The normal resting tonic innervation of the muscles remains, but there are no responses to visual input

Occurs at a later age than infantile eso, usually normal bino vision has existed prior to the onset of the condition

refers to eso which begins in the developmentally and neurologically normal child during first 6 months of life. Probable age of onset is at 2-4 months

Attributed partly or totally to either uncorrected hyperopic error of refraction and or high accommodative convergence / accommodation ratio

correcting any coexisting Hyperopia has minimal or no effect on the size of the eso

Convergent strabismus which develops suddenly without apparent etiology in school aged or adult px with previously normal bino vision

Caused by mechanical restriction or tightness of an eom or a physical obstruction of the eom

An eso resulting from primary sensory deficit or as a result of surgical intervention

Resulting from visual deprivation or trauma in one eye that limits sensory fusion e.g uncorrected anisometropia, unilateral cataract

Occurs after surgical overcorrection of an exotropia

In some cases, may escape diagnosis by conventional method

The px sometimes manifests diplopia, suppression, or anomalous retinal correspondence and at other times normal bino alignment with good stereopsis

Exo resulting from primary sensory deficit or as a result of some form of treatment for esotropia

Occurs after surgical or optical correction of an esotropia

Often is used to describe amblyopia which is potentially reversible by occlusion therapy

Refers to irreversible amblyopia

Term used in certain cases of reduced vision in which ocular pathology is not obvious. E.g alcohol, tobacco

Due to causes such as hysteria or malingering

As a result of long standing suppression when there is constant unilateral strabismus at all viewing distances during early childhood

Relatively rare and is secondary to high symmetric refractive error that remained uncorrected during early childhood before the age of 7 years or so

due to reduced vision caused by a physical obstruction to clear vision during early childhood resulting in severe light and form stimulus deprivation