48 terms

Binocular Vision Test 4

Aniseikonia - can be also be spelled "__________"
" Anisoconia"
The Advantages Of Binocular Vision.
1: The first and the foremost advantage of a binocular vision is ___________________
2: In addition to single vision it results in _________________ - the most precise kind of depth perception.
3: Enlargement of the ____________ of vision.
4: Compensation for the ___________ __________ and other differences.
1: Single Vision.
2: Stereopsis.
3: Field.
4:Blind spot.
Review Of The Retina.
1: 80 to 110 millions cones.
2: 4 to 5 millions cones.
3: Density of rods is _________ than that cones except in the macular regions.
4: The density of rods is greatest 7 degrees from the fovea and diminish toward the ora serrate.
5: Peripheral - designed for detecting gross from and motion, makes up most of the retina.
6: Central Retina - rich in cones has more ganglions cells per area than elsewhere, and is small portion of the entire retina.
3: Greater
Peripheral Vision.
1: Objects are _______ clear that in central vision.
2: Quite sensitive to _________, and _________ movements in the peripheral area will stimulate the retina and frequently elicits a turning of the _______ or ______ toward the motion.
Chang and Slight
Eye or Head.
Macula or Fovea.
1: When discussing the macula we usually refer to the area of ___________.
2: The fovea generally refers to the ___________ _________ of this area.
1: Darker Coloration.
2: Very center.
Areas of the Macula.
1: Fovea - depression - retinal neurons are displaced, leaving only ___________________ in the venter. Highest concentration of cones. Ratio of cones to ganglion (1:1)
2:rod free area ~(0.57mm) represents (1 degree) of visual field.
3: Foveola - densest population of cones
4: Parafoveal -
5: Perifoveal.
6: Peripheral Retina.
7: Useful colorful vision occupies an area approximately ____________ in diameter, the center is the macula lutea.
1: Photoreceptors.
7: 9mm.
Review of Visual Pathway - LGN.
1:________% of visual nerve fivers terminate in the lateral geniculate nucleus.
2: Resembles an asymmetric cone.
3: Regulates the flow of visual information insuring the most important information is sent to the _________.
1: 90%.
2: Cortex.
Review of Visual Pathway - visual Cortex.
1: Organized into ____________ layer and ____________ columns.
2: Certain areas are active during ___________ stimulation and others during ____________ movement.
3: ___________ ____________ and ______________ vision are the two function of the visual cortex.
4: The association areas in one hemisphere are connected to the corresponding areas in the other hemisphere the posterior portion of the corpus callosum.
1: Horizontal, Vertical.
2: Motion & during Color.
3: Contour analysis, Binocular.
Retino - cortical elements.
1: Technical terms: Neural signals that come from the ______________ to the primary visual cortex.
2: Laymans: Retinal images transferred into neural signal that the brain is "Interpeting."
1: Retina.
"__________________" fusion - mental integration of signals into a single perception. Occurs in the brain.
"_______________" fusion - coordinated eye movements that are performed in the order to maintain sensory fusion.
"_______________" fusion - involves similar macular images, under appropriate condition stereopsis results.
"________________" fusion - the images are from the peripheral areas of the eyes; some stereopsis may results.
Requirements for Normal Binocular Single vision.
1: __________ visual axis
2: The ability of the retino-cortical elements of function in association with each other to promote the fusion of two slightly dissimilar images i.e. _______________ fusion
3: the precise co-ordination of the two eyes for all direction of gazed, so that corresponding retino-cortical elements are placed in a corresponding area on each retina in order to deal with two images i.e. __________ _____________.
1: Clear.
2: Sensory.
3: Motor Fusion.
Single Binocular Vision - AKA Bifoveal fixation.
1: When the ___________ of both eyes are fixin on the ___________ object.
1: Foveas, Same.
1: Stereopsis- Horizontal slightly _______________ images are fused and seen in depth.
1: Different.
The Horopter
1: Imaginary curved line in horizontal plane.
2: Two corresponding points on each __________ focus on a point on the horopter.
3: A point 4 degrees to the right on the horopter would fall on each retina 4 degrees to the left of each fovea.
4: Moving off the horopter either way gives us _________________ images that the brain then fuses creating _____________.
{ Any point in ______________ of the horopter ( nearer than the point of fixation) would be shifted temporally on each retina and would no longer correspond creating ____________ diploma.}
{Any point _____________ the horopter (farther than the point fixation) would be shifted nasally on each retina and would no longer correspond creating _____________ diplopia.
Panum's Fusional Space.
1: An area in front of and behind the horopter where points can lie and the brain can still fuse these disparate images creating depth.
2: Beyond that __________________ _______________ occurs.
2: Physiological diplopia.
Physiological Doplopia.
1: All images that fall out of Panum's Fusional Space created physiological diploma but due to cortical processing our brain ________________ the awareness of this diplopia
1: Suppresses.
Three Grades of Binocular Vision.
1: Grade I: _____________________ macular perception is the most elementary type of binocularity. It occurs when the visual cortex perceives separate stimuli to the two eyes at the same time and concerns itself essentially with the absence of suppression.
2: Grade II: It represents ___________ ___________ with some amplitude. Not only are the two images fused, but some effort is made to maintain this fusion in spite of difficulties. This it implies a motor response added to simple sensory fusion.
3: Grade III: In the highest type of binocularity, no only are the images of two eyes fused, but they are blended to produce a ____________________ effect. This involves a perceptual syntheses at a higher level.
4: These three graded are not necessarily mutually exclusive, since fusion in the periphery, even showing motor responses, may exist coincidentally with the total absence of simultaneous foveal perception.
1: Simutaneous.
2:True Fusion.
Stereopsis - Disparity Sensitivity.
1: Fusion images within Panum's fusional area resulting in _______________ appreciation objects in depth.
Stereoscopic Acuity.
1: Measurement of the smallest binocular ____________ appreciation of visual objects in depth.
2: Measured in seconds of arc.
1: Disparity.
Binocular Disparity - two eyes do not see the same image.
1:Creation of 3-D images - _________ stereo images are created by shifting and superimposing red and blue imaged to mimic natural binocular disparities.
1: Red-Blue 3D
Components of stereopsis and index inter-retinal distant.
1: Images located about __________ degrees off dead center in the foveal gives ___________ _____________.
2: It diminishes exponentially to nil beyond 15 degrees eccentricity.
3: It also __________________ when moved in front of or behind the horopter.
4: Stereopsis cannot work beyond a certain critical distant between _________.
0.25, maximal, stereoacuity.
125-200 meters.)
How do you keep moving objects in focus?
1:You must continually shift Panum's fusional area by ______________ the eyes.
2: Objects moving closer require convergence.
3: Objects moving away require divergence.
4: We can measure the ability to converge or diverge with __________________ _________________.
5: Constantly shifting images to focus on the fovea _______________.
1: Verging.
4: Fusional Amplitudes.
5: Saccades.
Central Vs. Peripheral Binocular Vision.
1:Central Binocular Vision uses the central macula for activities such as knitting, writing.
2: Perpherial Binocular Vision usues more of the perpherial macula for depth including such activities as driving, and sports.
Retinal Rivatry/ Binocular Rivalry.
1: When dissimilar contours are presented to corresponding retinal areas fusion becomes _____________ and retinal rivarly may be observed.
2: Simultaneous excitation of corresponding retinal areas by dissimilar objects does not permit fusion and lead to _______________.
3: In order to remove this confusion, image from one of the eyes is ________________. This constant foveal suppression of one eye with cessation of rivalry lead to complete sensory dominance of the other eye, which is a major obsticle to binocular vision.
1: Impossible.
2: Confusion.
3: suppressed.
Binocular Rivalry.
1: What happens when the two eyes see __________ images.
2: Binocular color rivalry - images are different ________.
3: Binocular lusre - images differ in ______________.
4: Contour dominance - when only one eye sees.
2: Colors.
3: Lightness.
1: Images sized are different in each eye that the brain connot _____________ the images as one.
2: Can be caused by ____________ or ___________ surgery.
1: Fuse.
2: Anisometropia, Refractive.
There are two types of aniseikonia-
1: Static aniseikonia, in which the size of an images is different in each eye.
2: Dynamic aniseikonia, in which the eyes are forced to track vertically and laterally at different rates.
1: _________
2: __________
3: ______________ devises including synoptophor, Troposcope, Amblyoscope
4:_____________ lenses
5: Red filters
Stereo Test
Worth Four Dot
Test for Stereoacuity.
________ test
Haploscopic Devices
1: Titmus
2: Randot test
3: Lang
4: Frisby
Testing Motor Fusion Tests
1:______________ amplitudes
(Convergence, Divergence, Vertical.)
(Torsional, dont with haloscopic devices.)
2: _____________ base-out test.
1: Vergence.
2: 4 - Diopter.
Anomalous Retinal Correspondence ARC Also Known as Abnormal Retinal Correspondence.
1: Normal retinal correspondence -Fovea of one eye corresponds to the ____________ of the other eye.
1: Fovea
Abnormal retinal correspondence.
1: Brain attempts to develp new binocularity to __________ to ___________.
2: The quality of binocular single vision obtained in ARC varies from patient to patient, in some there is useful gross stereopsis while in the others binocular vision is rudimentary. the quality of binocular vision is usually inversly proportional to the angle of deviation.
1: Adapt, Strabismus.
Harmonious and unharmonious abnormal retinal correspondence.
1: _______________ - fovea of the straight eye and non-fovea point of the deviated eye work togeter, permitting single binocular vision of ___________ quality.
2: _____________ fovea of the straight eye and the non-fovea point of the deviated eye work together. PT still has _____________ __________ but not as expected. (We would expect a large deviation and measure a small one.)
Harmonious, Poor.
Visual, Confusion;
Assessment of relationship between the fovea of the fixing eye and the retinal area stimulated in the squinted eye.
1: ___________ striated glasses test.
2: ___________ filterd test.
3: ___________ - measuring the objective and subjective angles.
4: ___________ dot test in conjunction with cover test.
1: Bagolinis.
2: Red.
3: Synaptophore
4: Worth 4
Assessment of the visual direction of the two foveas.
1: ___________ _____________ _______________. (Hering Bielschowsky)
1: After Image Test.
Bagolini striated-glasses test.
1: Least ______________ of the test used to check for ________ ______________ _________.
2: Patient wears two lenses with striations placed _______________ degrees angles to each other. (One lens is at a 45 the other at 135.)
1: Dissociactive, Anomalous, Retinal, Corresponding.
2: 90.
1: After images test - test that show the ________ of the _______ used to determine ARC.
1: Alignment, Fovea.
1: MONOFIXATION SYNDROME also known as: Small angle ______________ or ___________.
2: Form of subnormal vison.
3: _________% of population.
4: No binocular ___________ vision however, the peripheral vision has __________ helping the eys stay slightly aligned.
5: Small angle deviation with central _____________ of deviation eye and binocular peripheral fusion.
6: Usually has a small (less then _______ degrees) ventral suppression scotoma.
7: Affected eye may be ________ and or/ _________.
1:Strabsmus, Microtropia.
3: 1
4: Central, Fusion
6: 3
7: Amblyopic, Anisotropic.
Causes of Monofixation syndrome.
1: Corrected _________ - commmon for patients who are surgically treated for congenital esotropia.
2: _______________.
3: Macular ______________.
1: Strabismus.
2: Anisometropia.
3: Lesion.
1: Generally __________.
2: Dianosed generally based on physical ___________.
3: Undiagnosed adults will present with subnormal stereovision, mild anisopmetreopia, subtle asymmetry in best-corrected vision.
1: Asymptomatic.
2: Examination.
Testing and results:
Prism cover test
*Should display less than _____ prism diopters of heterotropia with a simultaneous prism cover test.
*Alternate cover testing may result in ______ times greater measurement than simultaneous prism cover testing due to fusional vergence mechanisms.
*up to 1/3 will have ____ deviation with alternate cover
*__________ prism and cover measurements.
*used to measure the tropia component of the monofixation syndrome without dissociating the phoria and is _______ used in patients with small-angle strabismus.
4 Diopter BO prism test:
* one eye will test positive for suppression when tested at twenty feet
*Test has a _____ number of _______ negatives, especially if no manifest deviation is present.
Worth 4 Dot:
*At near (1/3 meter) testing peripheral fusion light extends _____ degrees of the retina.
*At distance the target is only _______ degrees of the retinal and slips into the suppression ________(patient should only visualize with one eye)
Stereoacuity Test:
*Reduced stereopsis, ranging from ______ arc sec-
*Stereopsis better at ______ than at ____
near than at distance
Bagolini lenses:
The eye with the suppression scotoma should have a line with a central _______ portion.