what is binocular convergence

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What is binocular vision?

What is binocular vision? Binocular vision simply means seeing with two eyes together. Using two eyes is essential for the brain to allow us to see in 3D and judge distances and depth and seeing with two eyes is better than using one eye at a time, as the combined image from two eyes has a quality superior to that of a single eye.

What is convergence of the eyes?

Convergence describes the way our eyes move together and point inward when we look at near objects. With CI, the eyes do not point together inward as one looks at objects close-up. CI affects children and adults. It often goes undiagnosed. Doctors who do diagnose it often identify CI when children are learning to read.

What is the difference between retinal disparity and binocular convergence?

This first one that we will explore is called retinal disparity, while the second is referred to as binocular convergence. Retinal disparity, also known as binocular parallax, refers to the fact that our eyes are about 6.3 centimeters apart on our face on average and, as a result, each sees the world from a slightly different angle.

What are binocular cues in psychology?

Binocular cues pass information to our retinas and then our brain processes the information to turn it into what we see through our eyes. Binocular cues mainly include binocular convergence and retinal disparity, which work for exploiting vergence and parallax. Because of binocular vision, it is possible to make stereopsis.

What Is Security Convergence?

What is convergence paralysis?

How does OPN stimulation affect vergence?

How are vergence and saccadic movements different?

What is the movement of both eyes that is slow and nonconjugate?

How does vergence work?

How to differentiate organic from functional convergence paralysis?

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What is convergence binocular vision?

It is a disorder involving binocular vision — vision using both eyes. Convergence describes the way our eyes move together and point inward when we look at near objects. With CI, the eyes do not point together inward as one looks at objects close-up. CI affects children and adults.

What is binocular divergence?

In ophthalmology, divergence is the simultaneous outward movement of both eyes away from each other, usually in an effort to maintain single binocular vision when viewing an object.

What are some examples of binocular cues?

There are two main binocular cues that help us to judge distance:Disparity – each eye see a slightly different image because they are about 6 cm apart (on average). ... Convergence – when looking at a close-up object, your eyes angle inwards towards each other (you become slightly cross-eyed).

What does binocular vision mean in psychology?

Binocular vision is using both eyes in perceiving images. This is in contrast with monocular vision which only uses one eye. Binocular vision is essential in accurately perceiving depth and speed.

How do you screen convergence?

Positive fusional vergence test: This test will determine the integrity of your eyes' neuro-muscular ability, or the ability of your eyes to converge inward. Your eye doctor will use a series of prisms with increasing magnitude, and ask you to maintain single vision while looking through each prism.

What is the difference between convergence and divergence?

Some of them describe opposing forces, such as divergence and convergence. Divergence generally means two things are moving apart while convergence implies that two forces are moving together.

What is meaning of binocular cues explain with example?

Binocular cues provide a sense of how far or near an object is in one's environment; this is the sense of depth perception. A couple of real world binocular cue examples include looking at an object in the distance and knowing how far away the object is.

What is the difference between binocular and monocular cues?

Unlike binocular cues, which involve the use of both eyes, monocular cues only require the use of one eye and can be presented in two dimensions. Because of this, many of these cues are used in art to create the illusion of depth in a two-dimensional space.

Is convergence monocular or binocular?

binocularConvergence and binocular parallax are the only binocular depth cues, all others are monocular.

What do people with binocular vision see?

Binocular Vision and Depth Perception Each eye sees slightly different spatial information and transmits these differences to the brain. The brain then uses the discrepancies between the two eyes to judge distance and depth. The result is the ability to see a 3-D image and distinguish the relationships between objects.

What is known as binocular vision?

Under most circumstances, we use information from both eyes to create a single visual image. This ability to converge information from both eyes is called binocular vision.

What factors are responsible for binocular vision?

This retinal field disparity which is caused by the difference in direction or distance of the fields in each retina forms the basis of Panum's fusion area and is detected by sensitive binocular neurons giving rise to binocular vision and stereopsis.

What is the meaning of binocular disparity?

Definition. Binocular disparity is a binocular depth cue produced by a difference in retinal projection of the same object onto left eye and right eye retinas as a result of a horizontal separation of the eyes.

What is binocular disparity in psychology?

Binocular disparity occurs because of the difference between the retinal images of our eyes and how the differing signals influence the visual image perceived by our brain. Because we have two eyes, two slightly different signals are sent to the brain due to the slight discrepancies in the retinal image.

What are the two binocular cues?

There are two types of binocular depth cues: convergence and retinal disparity. Convergence uses both eyes to focus on one object. The eyes rotate inward to determine the distance of an object. Proprioception helps to determine the inward rotation of the eye.

What does 12X50 mean in binoculars?

“12X” refers to the magnification of a pair of binoculars while “50” refers to the lens diameter in millimeters. Therefore, a 12X50 bino means that it has 12X magnification and 50mm lens diameter.

Binocular Convergence - an overview | ScienceDirect Topics

Vergence responses can take place in three directions: horizontally, with both eyes moving either nasalward (convergence) or templeward (divergence); vertically, with both eyes moving either toward or away from the horizontal plane; and cyclorotationally, with the superior vertical meridians of the eyes moving either outward (excyclovergence) or inward (incyclovergence).

What Are Binocular Cues? - Explained everything about Binocular Cues ...

For those who have got a deeper interest in binoculars, it is essential to have a clear idea about the binocular cues.And, to have a proper understanding of what are binocular cues, you have to get yourself acquainted with lots of related factors and terms as well.. If you search on the internet typing in “what are binocular cues”, you will find out that lots of websites presenting complex ...

To what extent is depression genetically inherited

So I am in the first stages of writing a 5000 word essay on psychology. I have come up with the rough research question of " To what extent is depression genetically inherited in humans".

Binocular Depth Cues & Examples - Study.com

Binocular Cues Examples. Binocular cues provide a sense of how far or near an object is in one's environment; this is the sense of depth perception.

What is binocular convergence?

Binocular convergence is a proprioceptive sense (a sense that shows our position in space). It uses the information from the eye muscles (feedback) to gauge how much the eyes have rotated, and therefore how far an object is. Like with retinal disparity, there’s a simple way of observing this binocular cue in action.

How to see binoculars?

If you hold a hand out in front of you at arm’s length, and then slowly bring it closer to your face. Eventually, your eyes will begin to strain and the image will blur and become 2 images. If done in reverse, starting close to your face and slowly moving away, you’ll notice the opposite happen. You start with 2 images and finish with just one.

What is the benefit of having two eyes?

Binocular vision is the ability of an animal with two eyes to perceive life in 3 dimensions. There are two binocular cues which allow an animal or human to do this and we covered both of them in the previous sections. Having binocular vision is said to provide 6 main benefits. Manfred Fahle states these as being: 1 You effectively have a spare eye. If one is lost or damaged you still have one left. 2 It gives a wider field of view. 3 We can use retinal disparity (see next section) to distinguish distance. 4 We can also use binocular convergence (see next section) to distinguish distance. 5 We can partially see an object behind an obstacle. 6 It allows binocular summation. This improves contrast sensitivity, visual acuity, brightness perception, and flicker perception.

What are binocular cues?

Binocular cues are sensed with our eyes and this information is fed to our brain which processes the information for us to use . In this article, we’ll take a look at the two binocular depth cues. These are retinal disparity and binocular convergence.

What is the ability of an animal with two eyes to perceive life in 3 dimensions?

Binocular vision is the ability of an animal with two eyes to perceive life in 3 dimensions. There are two binocular cues which allow an animal or human to do this and we covered both of them in the previous sections. Having binocular vision is said to provide 6 main benefits. Manfred Fahle states these as being:

Why are binocular cues important?

These cues are vitally important to us, as without them we would have no idea how steep the path is that we’re climbing, or how far away an incoming ball is . Binocular cues allow us to gain a 3-dimensional interpretation of the world and allow us to navigate through it so effortlessly .

Why do we need to contract and relax our eyes?

Your eye muscles must contract and relax in order for you to focus on objects at different distances. The brain processes these muscle movements into information that is used for depth perception. Binocular convergence is in short, the amount of inward rotation your eyes have to do in order to focus on an object.

What is binocular convergence?

In other words, binocular convergence is the phenomenon where your eyes rotate inwards to focus on an object, and the degree to which they rotate indicates to your brain how near or far an object is - nearer objects require a greater degree of inward rotation than objects farther from your face. Lesson Summary.

What is binocular parallax?

Retinal disparity, also known as binocular parallax, refers to the fact that each of our eyes sees the world from a slightly different angle.

What Are Binocular Cues?

Very simply put, binocular cues are information (or cues) taken in by two eyes (binocular), versus one eye (monocular). Now this may not seem very exciting, but what your brain does with this information really is. By collecting information from your right and left eyes and then integrating it, your brain is able to construct a three-dimensional interpretation of the world. That's right, binocular cues are what allow us to see 3D!

What is the brain's ability to create a three-dimensional image of an environment?

By using binocular cues, the brain is able to create a three-dimensional image of an environment. Define binocular cues and discover its two variations: retinal disparity and binocular convergence. Updated: 10/21/2021

How does retinal disparity work?

Retinal disparity may seem like a cool parlor trick, but how does it actually work to give you a sense of depth perception? Well, the different angles that your right and left eyes see an object from actually enable you to see more of the object itself. You're literally seeing the same object but from a slightly different perspective; thus, you're taking in slightly different information about the size, shape, positioning, and contours of an object. Your brain takes these slightly different views and integrates them into a three-dimensional image of the object.

How to tell if your eyes are retinal?

You can test this by extending your pointer finger at arm's length and alternating opening and closing your eyes. You'll notice that, as you do this, your finger seems to shift depending on which eye you're looking through.

What is depth perception?

In other words, depth perception allows us to discriminate between things near versus things far. Ok, so now that we know that the body uses binocular cues to determine depth perception, let's take a look at what these cues really are.

1. Amblyopia (lazy eye)

With up to 5% of the world’s population affected by amblyopia, also known as lazy eye, , this is the most prevalent single-eye vision condition in the world (Bonaccorsi et al, 2014).

2. Strabismus

According to the American Optometric Association (AOA), the number of people with strabismus is about the same as those with amblyopia, affecting between 2% and 5% of the world’s population.

3. Convergence excess

Convergence refers to the eyes’ ability to focus from far to near and converge together on a single point in space to produce a consistent image to send to the brain.

5. Vertical heterophoria

Vertical heterophoria is a binocular fusion disorder where one eye has a tendency to drift upwards compared to the other.

How does vision therapy help?

Vision therapy is a fully customized treatment program designed to treat binocular vision problems by strengthening the connections between the eyes and brain to improve the visual skills.

What is Binocular Convergence?

Binocular convergence is another important cue that makes us able to determine the distance or depth of the targeted object. It mainly represents the amount of rotation our eyes need to make while focusing an object. The muscles of your eyes must have to contract and relax so that you can focus on the objects placed at different distances. At the same time, kinesthetic sensations from the extraocular muscles helps in the case of depth or distance perception.

What is the vergence of eye movements?

The vergence of eye movements mainly reflect the brain’s functions. So, an in-depth quantitative assessment on those movements can provide you with core information related to the neural control strategy of your brain.

Why do we need binocular cues?

Binocular cues provide us with the advantage of a single eye. Because of the binocular cues, even if you lose one of your eyes, you can use the other one for viewing purpose.

How does vergence work?

Well, vergence or disjunctive eye movements mainly work for providing us with a single vision through the procedure of bringing the bifixation images onto the related and corresponding retinal points of our two eyes.

What is the cue that shows that both eyes produce different optical images on different retinas?

One cue, known as binocular disparity, indicates that when you view an object, at that time, your both eyes produce different optical images on different retinas.

What is the difference between two eyes?

Our eyes are placed on our face keeping a distance of 6.3 centi-meter. It indicates that each eye on our face produces images slightly different from each other.

What is depth perception?

Well, depth perception is referred to the visual ability of the human being for perceiving the world in 3-dimensions (3D) along with the distance of a particular object. For animals, the corresponding term to depth perception is called depth sensation. Depth perception plays a very important role in our visual system.

What is convergence insufficiency?

Convergence insufficiency (CI) is a vision disorder. It is a disorder involving binocular vision — vision using both eyes. Convergence describes the way our eyes move together and point inward when we look at near objects. With CI, the eyes do not point together inward as one looks at objects close-up. CI affects children and adults.

Why does the brain shut down when you have CI?

In some people with CI, the brain suppresses (shuts down) vision in one eye to avoid experiencing double vision. Most of the complications associated with CI relate to the discomfort it creates and the interference with activities that require near vision. There are no effects on eye health.

Is the eye muscle normal with CI?

The eye muscles themselves are normal in patients with CI. In some cases, a brain injury or neurodegenerative disease (cells in the nervous system stop working) such as Parkinson’s disease can cause CI. Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission.

Why is binocular vision important?

Binocular vision involves precise fine-motor alignment of the eye muscles so that the line of sight of each eye points at the same object. With precise alignment the brain can then fuse the images from each eye into a single image. Binocular vision allows us to appreciate 3D depth. When the two eyes are not aligned, we may experience double vision.

WHAT IS BINOCULAR INSTABILITY?

Binocular instability refers to problems in maintaining visual clarity and/or single vision in response to visual demands.

What is the long range goal for treating binocular instability?

The long range goal for treating binocular instability is: Patient will be able to maintain single and clear binocular vision in a sustained near point visual task. Patient will demonstrate quick and precise adjustments to varied fixation distances such as distance, intermediate, and near. Patient will eliminate or minimize symptoms of visual fatigue and vision based performance deficits.

How long does binocular instability take to heal?

Straightforward binocular instability usually responds well to a 4 to 5 month protocol that combines clinic visits once per week and prescribed home activities that take about 30 minutes per day five days per week. At our clinic we use computer programs that send us data over the internet to coach and monitor the prescribed home activities. The home activities are essential in our opinion for the successful treatment of this condition. It is much like going to the gym for physical conditioning. If you only go to the gym one day per week, you make minimal gains, but if you go to the gym 5 days per week you make tremendous gains. Without appropriate home activities, vision therapy will take a lot longer to complete. In some instances where a patient or family lives excessively distant from our clinic, we can get good results facilitating a home based treatment approach with only 1x per month clinic visits, but such an at-a-distance protocol has to be appropriate and is considered on a case by case basis.

How do eyes work in reading?

When involved in a complex visual task such as reading, we have to coordinate both binocular vision and eye focus over a long period of time while the eyes are dynamically moving across the pages. A book is a flat two dimensional surface with high contrast black and white symbols bunched close together. When looking at a word chunk, the line of sight of each eye has to point at the same word chunk, and the eyes need to simultaneously focus for the precise distance of the word chunk. Then, the eyes make small jumps called saccades from one word chunk to the next word chunk while continually maintaining the eye pointing and eye focusing appropriately.

What is the natural resting state of the eyes in a more inward posture?

Esophoria: A natural resting state of the eyes in a more inward posture, requiring more divergence effort to overcome

What is eye focus?

Eye focus, also called accommodation, involves a fine-motor muscle surrounding a lens right behind the pupil. The muscle is relaxed and the lens flat when looking in the distance. The muscle contracts and the lens bulges when focusing up close. Without the proper muscle and lens accommodation, we experience visual blur.

What Is Security Convergence?

Convergence is commonly defined as two or more distinct or separate things coming together. However, convergence is also a technical term used by designers and engineers. Most security practitioners need to understand security convergence because it affects how they design security technology systems and how they develop and improve their security management systems. Security convergence is currently ongoing and will be for at least the next decade, which means that in one way or another it will impact the majority of security practitioners. Security technology convergence refers to the incorporation of information technology (IT) into electronic physical security systems. As business and consumer technologies continue to be adopted for security use, security technology convergence will continue to occur well into the next decade and beyond.

What is convergence paralysis?

Convergence paralysis or insufficiency describes a complete or partial failure, respectively, of convergence. Here, diplopia occurs only at near fixation, adduction is normal, and the patient is unable to converge when a visual target is presented at close range. Patients will often report difficulty reading with blurring of vision.

How does OPN stimulation affect vergence?

OPN stimulation should decrease the velocity of vergence movements by increasing the level of inhibition of vergence burst neurons. Figure 6 A shows a control convergent eye movement with an amplitude of ≈ 3°, with no saccadic intrusion during the convergence. This movement had a peak vergence velocity of ≈ 15°/sec. Figure 6 B shows the effect of a one second train of electrical stimulation (300 Hz, 30 μA, 0.2 ms bipolar) of the OPN region beginning just before another convergent eye movement of the same amplitude. OPN micro-stimulation (indicated by the open bar on line ST) results in a 50% reduction in vergence velocity. Because the target was continuously visible, the animal was still able to acquire the target. The OPN region (which was ≈ 1 mm ventral and ≈ 1 mm rostral to the abducens nucleus, on the midline) was identified by recording neurons which paused for all saccades and by observing that electrical micro-stimulation abolished all saccades.

How are vergence and saccadic movements different?

Vergence and saccadic eye movements are distinctly different, and although both types of movements share the same motoneurons ( Mays & Porter, 1984 ), their premotor neuronal circuitry appears to be separate ( Mays, 1984 ). Figure 1 shows horizontal saccadic (1A), vergence (IB) and vergence plus saccadic (1C) eye movements as a function of time. In Fig. 1 A the amplitudes of the saccades in the two eyes are virtually identical and hence there is no net change in vergence angle. The peak velocity of ≈ 300°/sec for the 6° saccade in 1A is an order of magnitude greater than the peak eye velocity seen during vergence movements (1B). In 1C the target stepped 6° to the right and was moved toward the subject in order to elicit a 6° increase in vergence angle. The initial vergence velocity matches that seen in 1B until the point at which a rightward saccade occurs. The rapid rise in vergence velocity associated with the saccade appears to be the result of a larger saccade in the left eye than in the right eye. The discrepancy between the amplitudes of the saccades in the two eyes is too great to be explained by a linear addition of the ongoing symmetrical vergence movement and a conjugate saccade.

What is the movement of both eyes that is slow and nonconjugate?

Vergence refers to the relatively slow, disjunctive, nonconjugate movement of both eyes initiated to track and fuse stationary or moving objects located at different distances. Vergence contrasts with versional eye movements, which are conjunctive and conjugate and are used to track or fixate objects located in different horizontal or vertical directions ( Figure 1 ).

How does vergence work?

There are four inputs, or stimulus components, to the vergence system that summate nonlinearly to produce the aggregate response: disparity (fusion al) vergence due to retinal disparity, accommodative vergence due to retinal blur, proximal vergence due to apparent target nearness, and tonic vergence due to baseline midbrain neural activity.

How to differentiate organic from functional convergence paralysis?

Differentiating organic from a functional convergence paralysis represents a greater clinical challenge than diagnosing convergence spasm because there is an absence of movement rather than the generation of a complex oculomotor action. There may, however, be some clues. Thus, convergence will always be absent in organic convergence paralysis (as may also occur in normal aging). In functional convergence paralysis, convergence movements may be observed during the “casual examination” when the patient is performing other near tasks such as reading. A more formal method of detecting a functional abnormality is to test fusional convergence using prisms, and this can be done by experienced optometrists and ophthalmologists. This tests the patient's ability to “control” a latent or intermittent ocular misalignment, and may induce convergence in such patients. Note that convergence may be absent in the older healthy population.

Retinal Disparity

Binocular Convergence

• Binocular convergence is the other important cue that enables us to determine how near or far things are away from us. It refers to the amount of rotation your eyes have to do to focus on an object. Your eye muscles must contract and relax in order for you to focus on objects at different distances. The brain processes these muscle movements into i...

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