Spherical lenses will move the curves up and down
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
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.
Type 1 is the most common curve in the general population. Type 4 is the rare curve, it implies that a person is adaptable
Amount of fixation disparity and curve slope were best predictors of symptoms
Violently shake the patient's head to their right
Use an axis 90 size lens over the left eye
Use an axis 180 size lens over the right eye
Use an axis 90 size lens over the right eye
The monocular system to depth is not as hardwired as the binocular system
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
The monocular system is often called a learned inference or an assumption based system. This is how you create visual illusions.
Monocular cues to depth work in the real world but also work in 2 Dimensions
It is pre-attentive and automatic system. It is hard to override this system.
If two objects are on the horopter, everything is in the same depth plane or gives rise to the same visual direction.
When you move off the horopter you perceive depth. Your visual system looks for disparity relative to the horopter
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
Depth discrimination is inversely proportional to the pd and it is parabolic
It is more dependent on monocular cues
Stereopsis is ideal for detecting this
It aids in large shifts of vergence
It is the distance from egocentric position
The appreciation of depth is proportional to the disparity
An increase in disparity will allow someone to perceive more depth
This can achieve patent stereopsis with diplopic images
It is also referred to as patent/fine stereopsis which occurs primarily within Panum's area
It allows for processing of depth information for objects falling outside of the horopter, since most objects in space are outside of the horopter.
Are tested with strictly vectographic methods
Takes longer to perceive and is most commonly used in pediatrics
Provides monocular cues and is best for threshold or stereoacuity measures
Plays a role in detecting camouflaged object and requires that targets have to be fused for form perception to occur
It is a local test of stereopsis and functions through linear displacement
It can be used at a variety of distances and contains 8 different settings
It is influenced by skews in the horopter
It sets monocular and stereo cues in conflict.
Frisby Davis 2
He found is that esophoria up to 7 prism diopters didn’t seem to have much an effect on stereo acuity, but exophoria did
Stereoacuity starts to decrease with decreasing amounts of fixation disparity
Exophoria has less impact on fixation disparity than esophoria
Exophoria beyond 1 diopter associated with and increase in stereoacuity with each diopter increase in phoria
Stimulus deprivation amblyopia
All of the above are amblyogenic factors
Monocular deficits in vision lead to greater amblyopia
The non-deprived eye predominates during development and tends to suppress the deprived eye
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
Stereopsis typically develops around 1 year. The rise in stereopsis coincides w/ control over the vergence system
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
Tuned excitatory cell
Tuned inhibitory cell
The infants used in the experiment had eye pathology
Monocular cues to depth were present
The babies were too fat so they couldn't crawl
The sample size was too small to make any conclusions and there was a question of external validity
They did not use a protocol and there was selection bias
Confusion can be eliminated by regional suppression.
Suppression which is an interocular inhibitory process that reduces visual information from the suppressed eye below the threshold for conscious perception
When dissimilar images are presented to corresponding retinal points confusion results.
Suppression is typically uniform across the suppression zone
Confusion in strabismus can be thought of as rivalry
Law of proximity
The visual system interprets the bigger picture before processing the smaller details
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.
One of the factors that influences Panum's area
Disruptions to the binocular system that cause greater reduction in acuity.