Binocular Vision - Midterm 2

31 Questions | Total Attempts: 166

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Eye Quizzes & Trivia

Fixation disparity and AC


Questions and Answers
  • 1. 
    Which of the following statements is false regarding fixation disparity curves?
    • A. 

      Spherical lenses will move the curves up and down

    • B. 

      They tell us the measure of vergence adaptation, if it is a fast or disparity vergence system. It also tells us slow or vergence adaptation system

    • C. 

      To calculate the AC/A ratio you can plot each lens/prism pair of points, For each lens power find the corresponding prism power that produces the same fixation disparity value.

    • D. 

      Type 1 is the most common curve in the general population. Type 4 is the rare curve, it implies that a person is adaptable

    • E. 

      Amount of fixation disparity and curve slope were best predictors of symptoms

  • 2. 
    We are inducing aniseikonia with the Space Eikonometer and want to create a tilt away from the right eye. What would be the best way to accomplish this? 
    • A. 

      Violently shake the patient's head to their right

    • B. 

      Use an axis 90 size lens over the left eye

    • C. 

      Use an axis 180 size lens over the right eye

    • D. 

      Use an axis 90 size lens over the right eye

  • 3. 
    Closer objects will move in an opposite direction as the eye movement and farther objects will move in the same direction as the eye. Which monocular cue to depth does this statement describe?
    • A. 

      Linear perspective

    • B. 

      Motion parallax

    • C. 

      Parallelism

    • D. 

      Aerial perspective

  • 4. 
    Which of the following statements regarding the monocular system is false?
    • A. 

      The monocular system to depth is not as hardwired as the binocular system

    • B. 

      Texture gradients and linear perspective are things that enhance relative size and relative height and are also examples of monocular cues to depth used by the monocular system

    • C. 

      The monocular system is often called a learned inference or an assumption based system. This is how you create visual illusions.

    • D. 

      Monocular cues to depth work in the real world but also work in 2 Dimensions

    • E. 

      It is pre-attentive and automatic system. It is hard to override this system.

  • 5. 
    The stereoscopic system is a ______ (relative or absolute) depth pereception system whereas monocular system is more of a ______ (relative or absolute) depth perception system. 
  • 6. 
    Select the false statement
    • A. 

      If two objects are on the horopter, everything is in the same depth plane or gives rise to the same visual direction.

    • B. 

      When you move off the horopter you perceive depth. Your visual system looks for disparity relative to the horopter

    • C. 

      The tests you have clinically often don’t truly measure stereoacuity because true stereoacuity is a hyperacuity that goes down to seconds of arc and can go down to four or five seconds of arc in a well trained good observer

    • D. 

      Depth discrimination is inversely proportional to the pd and it is parabolic

  • 7. 
    Which statement refers to Relative depth perception?
    • A. 

      It is more dependent on monocular cues

    • B. 

      Stereopsis is ideal for detecting this

    • C. 

      It aids in large shifts of vergence

    • D. 

      It is the distance from egocentric position

  • 8. 
    Which of the following statements does not refer to Quantitative stereopsis?
    • A. 

      The appreciation of depth is proportional to the disparity

    • B. 

      An increase in disparity will allow someone to perceive more depth

    • C. 

      This can achieve patent stereopsis with diplopic images

    • D. 

      It is also referred to as patent/fine stereopsis which occurs primarily within Panum's area

    • E. 

      It allows for processing of depth information for objects falling outside of the horopter, since most objects in space are outside of the horopter.

  • 9. 
    Local stereopsis: 
    • A. 

      Are tested with strictly vectographic methods

    • B. 

      Takes longer to perceive and is most commonly used in pediatrics

    • C. 

      Provides monocular cues and is best for threshold or stereoacuity measures

    • D. 

      Plays a role in detecting camouflaged object and requires that targets have to be fused for form perception to occur

  • 10. 
    Which of the following statements is not true about the Verheoff test?
    • A. 

      It is a local test of stereopsis and functions through linear displacement

    • B. 

      It can be used at a variety of distances and contains 8 different settings

    • C. 

      It is influenced by skews in the horopter

    • D. 

      It sets monocular and stereo cues in conflict.

  • 11. 
    Which one of the following is a global test of stereopsis and is similar to the TNO test?
    • A. 

      Verheoff

    • B. 

      Stereofly/Titmus

    • C. 

      Lang

    • D. 

      Frisby Davis 2

  • 12. 
    You are playing with a Magic eye. In order to achieve this you look beyond the target and diverge your eyes. What type of fusion is this?
    • A. 

      Relaxed Fusion

    • B. 

      Othoptic fusion

    • C. 

      Chiascopic fusion

    • D. 

      Fechner's Fusion

  • 13. 
     Saladin in ’95  studied 2000 military subjects. He measured their distance stereo with the Howard-Dolman and he measured their phoria at distance.  Which of the following statements is most correct concerning his findings?
    • A. 

      He found is that esophoria up to 7 prism diopters didn’t seem to have much an effect on stereo acuity, but exophoria did

    • B. 

      Stereoacuity starts to decrease with decreasing amounts of fixation disparity

    • C. 

      Exophoria has less impact on fixation disparity than esophoria

    • D. 

      Exophoria beyond 1 diopter associated with and increase in stereoacuity with each diopter increase in phoria

  • 14. 
    You have a 75% change of seeing an object monocularly. What would be the probability of seeing the object with two eyes according to a probability summation? 
    • A. 

      75%

    • B. 

      86%

    • C. 

      94%

    • D. 

      99%

  • 15. 
    Which of the following is not an amblyogenic factor?
    • A. 

      Anisometropia

    • B. 

      Meridional amblyopia

    • C. 

      Stimulus deprivation amblyopia

    • D. 

      Strabismus

    • E. 

      All of the above are amblyogenic factors

  • 16. 
    Select the false statement regarding developmental aspects of binocular vision
    • A. 

      Monocular deficits in vision lead to greater amblyopia

    • B. 

      The non-deprived eye predominates during development and tends to suppress the deprived eye

    • C. 

      Amblyopia is defines as the decrease in VAs that is present in the absence of any pathologic abnormalities. Amblyopia is usually caused by a disruption in binocularity during the critical period

    • D. 

      Stereopsis typically develops around 1 year. The rise in stereopsis coincides w/ control over the vergence system

    • E. 

      If I had bilateral reduction in vision in each eye ( a high hyperopia in each eye) I wouldn’t have as much of reduction in vision or amblyopia from that- it’s the asymmetry that causes the deeper amblyopia

  • 17. 
    There are 4 types of cells used in the detection of disparity. Which binocular cell is used in the detection of coarse stereo
    • A. 

      Tuned excitatory cell

    • B. 

      Tuned inhibitory cell

    • C. 

      Far cell

    • D. 

      Giant cell

    • E. 

      Small cell

  • 18. 
    The Visual cliff experiment was considered a landmark study in the field of stereopsis. However the study initially received alot of criticism. What was the reason for all the hatin'? 
    • A. 

      The infants used in the experiment had eye pathology

    • B. 

      Monocular cues to depth were present

    • C. 

      The babies were too fat so they couldn't crawl

    • D. 

      The sample size was too small to make any conclusions and there was a question of external validity

    • E. 

      They did not use a protocol and there was selection bias

  • 19. 
    Which statement is not true?
    • A. 

      Confusion can be eliminated by regional suppression.

    • B. 

      Suppression which is an interocular inhibitory process that reduces visual information from the suppressed eye below the threshold for conscious perception

    • C. 

      When dissimilar images are presented to corresponding retinal points confusion results.

    • D. 

      Suppression is typically uniform across the suppression zone

    • E. 

      Confusion in strabismus can be thought of as rivalry

  • 20. 
    After-effects ( like the Buddha illusion) can be used to test for binocularity. 
    • A. 

      True

    • B. 

      False

  • 21. 
    A patient who had a lesion at the optic chiasm would have a bitemporal defect. If I have a lesion at the optic chiasm, then I lose all my crossing over fibers. The nasal fibers would be lost. Therefore the only way I would get stereo would be with bitemporal stimulation
    • A. 

      True

    • B. 

      False

  • 22. 
    Things that are close together will tend to group together, which Gestalt principle is that? 
    • A. 

      Good continuation

    • B. 

      Law of proximity

    • C. 

      Common region

    • D. 

      Common fate

  • 23. 
    Elements that change at the same time group together, which Gestalt principle is that?
    • A. 

      Parallelism

    • B. 

      Symmetry

    • C. 

      Synchrony

    • D. 

      Connectedness

  • 24. 
    Occlusion relates to the concept of relatability.  It’s that whatever is being covered, two ends of it have to make sense to your visual system. Your visual system is more likely to interpret things as occluded when the thing that it is occluding makes sense or has good continuation to it
    • A. 

      True

    • B. 

      False

  • 25. 
    What is the global superiority effect?
    • A. 

      The visual system interprets the bigger picture before processing the smaller details

    • B. 

      When placing a neutral density filter over one eye. When you close the eye with the filter the object looks brighter. The visual system does not add the brightness from the 2 eyes.

    • C. 

      One of the factors that influences Panum's area

    • D. 

      Disruptions to the binocular system that cause greater reduction in acuity.