Fixation ocular. Medical search. Frequent questions

These constant oscillations are called fixational eye movements, and they include ocular microtremor, microsaccades, and drift. (wikipedia.org)
Ocular tremor is the smallest of these movements, and it often overlaps with drift. (wikipedia.org)
Ocular microtremor is smaller than the other fixational eye movements of microsaccades and drift. (wikipedia.org)
To capture the neural signals associated with fixation categories, we analyzed electroencephalograms (EEGs) and eye movements recorded simultaneously in a free-viewing contour search task. (lu.se)
It can be due to refractive error, binocular fusion abnormalities, or neuromuscular anomalies of ocular movements. (nih.gov)
Indeed, ocular saccades are very fast movements of both eyes, in the same direction and with the same amplitude. (scirp.org)
Brain dysfunction must explain the abnormal visual responses, as abnormal ocular structures, abnormal eye movements, and refractive error do not. (childrenshospital.org)
There are four basic types of eye movements: saccades, smooth pursuit movements, vergence movements, and vestibulo-ocular movements. (pursuantmedia.com)
Two phases of eye movements associated with blinking can be distinguished: an initial dynamic ocular rotation that occurs with every blink and a subsequent sustained phase 1 that occurs only when closure of the eyelid is prolonged. (arvojournals.org)
To investigate the three-dimensional ocular kinematics during the initial phase of blinks, we recorded eye movements in healthy human subjects with dual search coils that were modified to exclude torsional artifacts. (arvojournals.org)

We found that precursor fixations were preceded by the largest saccades among the fixation categories. (lu.se)
For this, he performs saccades, vergences and eye fixations, multiple and in all directions. (scirp.org)
The size of the blue areas represents the duration of the ocular fixations and the lines represent the ocular saccades. (neurosciencenews.com)
What are saccades and fixations? (pursuantmedia.com)
Saccades are the type of eye movement used to move the fovea rapidly from one point of interest to another, while a fixation is the period of time where the eye is kept aligned with the target for a certain duration, allowing for the image details to be processed. (pursuantmedia.com)
Results indicated that the average reading time by word, number of ocular fixations and number of regressive saccades, varied according to complexity and theme of texts. (bvsalud.org)

Convergence during viewing a near target did not increase the response (gain) of her vestibulo-ocular reflex. (mssm.edu)
Whenever the target failed to appear as expected, the gaze and head velocity trajectories continued to be made, indicating that predictive suppression of the vestibulo-ocular reflex (VOR) was taking place in darkness. (strath.ac.uk)

SR and LR Union Suture for the Treatment of Myopic Strabismus Fixus: Is Scleral Fixation Necessary? (hindawi.com)
Retrospective review of 32 eyes of 22 patients with myopic strabismus fixus who had undergone union suture of superior rectus (SR) and lateral rectus (LR) with or without scleral fixation, and follow-up longer than 6 months at Hong Kong Eye Hospital from 2006 to 2013. (hindawi.com)
As scleral fixation on pathological myopic eyes could impose potential risk of scleral perforation, our study aims to report the surgical techniques and evaluates and compares the results of patients with myopic strabismus fixus patients who had undergone union suture of SR and LR with or without scleral fixation. (hindawi.com)
Strabismus is defined as acquired if the deviation is noticed after 6 months of age, following a presumed normal ocular alignment. (nih.gov)
Benefiting from blended learning opportunities, you will learn about paediatric ophthalmology, strabismus (ocular misalignment), ocular motility disorders, and other eye and vision health issues and diseases. (ucl.ac.uk)

Seeing two objects instead of one ( diplopia ) with a binocular view can arise from ocular misalignment caused by lesions of the brainstem and cerebellum. (medscape.com)
We aimed to assess the objective ocular cyclodeviation between monocular occlusion and binocular conditions using fundus photography. (bmj.com)
We also examined the direction of ocular rotation under the binocular condition regarding the monocular condition. (bmj.com)
A series of studies were performed to evaluate adaptation using varying demands for accommodation and vergence, stimulated by binocular fixation at near (33 cm), through the addition of +2D and -2D over corrective lenses (closed loop accommodation) and using 10 base-out prisms (open-loop accommodation at 4M). (uwaterloo.ca)
For the open-loop condition (obtained using 0.5 mm pinhole pupils), binocular accommodation and tonic vergence (distance heterophoria through pinhole pupils) were determined at frequent intervals when binocular fixation was sustained at 4M for 20 min. (uwaterloo.ca)
First, it outlines that the addition of +2D and -2D lenses alters both accommodation and near phoria during sustained binocular fixation, which can be explained based on the models of accommodation and vergence. (uwaterloo.ca)

Ocular Torsion may be purchased as an ad on option. (arringtonresearch.com)
The Small Red and Green Maddox lenses are used to measure ocular torsion. (bernell.com)
This provides a measure of the patient's ocular torsion. (bernell.com)

Specific tools, known as piezoelectric probes or piezoelectric strain gauges, are commonly used to measure ocular microtremor. (wikipedia.org)

Downbeat nystagmus, cerebellar oculomotor signs, impaired visual fixation suppression of the vestibular-ocular reflex, vertiginous symptoms, and visual disturbances frequently co-occur at disease onset. (movementdisorders.org)
Dive into the research topics of 'Effects of visual fixation and convergence on periodic alternating nystagmus due to MS'. Together they form a unique fingerprint. (mssm.edu)
this test can detect nystagmus and palsies of ocular muscles. (msdmanuals.com)

Fukuyama congenital muscular dystrophy (FCMD) is one of the congenital muscular dystrophies, showing central nervous system (CNS) and ocular lesions, in addition to muscular dystrophy. (intechopen.com)

Studies of ocular lesions are not so many, compared with those of the muscle and CNS. (intechopen.com)
In this chapter, ocular lesions of fetal and child FCMD patients are presented, especially focusing on pathological findings of the retina, and functions of fukutin are discussed. (intechopen.com)

We investigated the mechanisms underlying inter-ocular suppression during continuous flash suppression (CFS) and dichoptic visual masking using a transient onset target stimulus and a variety of stimulus/mask temporal manipulations. (frontiersin.org)
We show that target duration, timing of target onset, and mask frequency are key aspects of inter-ocular suppression during CFS with transient targets. (frontiersin.org)
Several psychophysical techniques make stimuli invisible via inter-ocular suppression: dissimilar images are presented to the left and right eyes, which leads to the suppression of one of the images from conscious perception. (frontiersin.org)

Eyestrain, or asthenopia, a condition arising from the efforts made by individuals to keep their eyes adjusted for seeing, was reviewed and discussed with emphasis on fixation, convergence and control of the size of the pupil. (cdc.gov)

Rather, its spatial resolution lies at the scale of ocular dominance columns. (frontiersin.org)

Error rate as well as dwell time, fixation count, fixation duration and revisits were analysed using a linear mixed-effects model analysis to compare TML-coded with non-TML-coded labels. (bmj.com)
Gaze position and fixation duration displayed over scene image as the subject views it. (arringtonresearch.com)

Based on the gaze-dependent pattern of trajectories, they concluded that the combined action of the inferior and superior recti muscles is sufficient to explain ocular rotation during short blinks. (arvojournals.org)
For the evaluation of the performances of a toric system, the combination of corneal topography imported from CSO topographers and ocular aberration, makes it possible to distinguish whether any astigmatic residue is due to a rotation of the lens or to an incorrect calculation. (csoitalia.it)

2015) A retrospective survey of ocular abnormalities in pugs: 130 cases. (rcvsknowledge.org)

Many surgical methods had been described so far, including vertical muscle transposition, ipsilateral medial rectus recession and ipsilateral lateral rectus resection, and posterior fixation suture [ 6 ]. (hindawi.com)

Ocular manifestations of human immunodeficiency virus (HIV) infection are common. (medscape.com)

Further, myopic children also showed variations in other ocular motor parameters such as higher accommodative lags, greater variability of accommodative response, larger accommodative after-effects, and higher AV/A ratios compared to emmetropes. (uwaterloo.ca)

After a light fixation target is held up in front of the patient, the patient can rotate the lenses until both lines are parallel to the ground. (bernell.com)

Heterophoria is defined as an ocular deviation kept in control by a fusional mechanism. (nih.gov)

To capture the neural signals associated with fixation categories, we analyzed electroencephalograms (EEGs) and eye. (lu.se)
However, it is not clear whether we may obtain a more precise spatial localization of the focus of attention based on the EEG signals during central fixation. (plos.org)
While we find a surprisingly weak correlation between the preferred orientation of multi-unit activity and gamma-band LFP recorded on the same tetrode, there is a strong correlation between the ocular preferences of both signals. (frontiersin.org)

Depending on where you experience the discomfort, eye pain can fall into one of two categories: Ocular pain occurs on the eye's surface, and orbital pain occurs within the eye. (pursuantmedia.com)
Ocular pain refers to discomfort around the outside of the eye, while orbital pain is usually felt deep behind the eye. (pursuantmedia.com)
Ocular discomfort and other symptoms of eyestrain at low levels of illumination. (cdc.gov)

We concluded that precursor fixations play a pivotal role in visual perception, marking the continuous occurrence of transitions between exploratory and exploitative modes of eye movement in natural viewing behavior. (lu.se)
In this study, an exemplar-based classifier was developed to predict which decision strategy may underlie an empirical ocular search behavior. (aisnet.org)

Accommodation and vergence are two interacting ocular motor systems that function to maintain clear and single vision across a wide range of distances. (uwaterloo.ca)
Consistent with the models of accommodation and vergence, the thesis highlights that it is necessary to measure changes to both accommodation and vergence when evaluating the response of the ocular motor system. (uwaterloo.ca)

Ocular tremor (ocular microtremor) is a constant, involuntary eye tremor of a low amplitude and high frequency. (wikipedia.org)
The frequency of ocular microtremor has been found to range from 30 Hz to 103 Hz, and the amplitude is approximately four thousandths of a degree. (wikipedia.org)
The measured frequency and amplitude of ocular tremor have been found to vary. (wikipedia.org)
Independent of the effect of saccade length, EEG amplitude was enhanced in precursor fixations compared with the other fixation categories 200 to 400 ms after fixation onsets, most noticeably over the occipital areas. (lu.se)

In general, the CD4 + T-lymphocyte count has been used to predict the onset of certain ocular infections in patients who are HIV positive. (medscape.com)

The predictive value of the CD4 + T-cell count for ocular complications in HIV infection has been called into question by reports of CMV retinitis in patients with CD4 + cell counts higher than 200 cells/mL. (medscape.com)

It has also been suggested that ocular tremor is a result of the eye being balanced between opposing muscles. (wikipedia.org)

Due to these difficulties in measurement, fewer studies have been performed on ocular microtremor, leading to the phenomenon of ocular tremor not being well-understood. (wikipedia.org)
The measurement conditions differ from the viewpoint of the presence or absence of one eye occlusion in the two tests: ocular structural imaging and visual field testing. (bmj.com)
We evaluated whether or not a difference exists in the ocular cyclodeviation due to the difference in the measurement condition using an objective cyclic angle and found that there was no significant change. (bmj.com)
Real-time measurement of the ocular wavefront is indispensable during the evaluation of the accommodative phases. (csoitalia.it)

This is the monthly Vision Center of Excellence Ocular Trauma and Vision Readiness Video TeleConference (VCE OTVR VTC). (dhaj7-cepo.com)
This conference discusses ocular trauma cases and vision readiness topics from around the Department of Defensce (DoD), Defense Health Agency (DHA), and U.S. Department of Veterans Affairs (VA). (dhaj7-cepo.com)

Sebbag, L. and Sanchez, R.F. (2022) The pandemic of ocular surface disease in brachycephalic dogs: The brachycephalic ocular syndrome. (rcvsknowledge.org)

While non-contact methods of measuring ocular tremor have been found, they are not typically used due to their low resolution. (wikipedia.org)
Describe the different methods for intrascleral fixation of IOLs. (dhaj7-cepo.com)

A conventional visual fixation paradigm was used as a control task, to assess location and extent of visual receptive field of neurons. (nih.gov)
Eye tracking studies suggest that refixations-fixations to locations previously visited-serve to recover information lost or missed during earlier exploration of a visual scene. (lu.se)
On the other hand, visual fixation allows the subject to identify an object by observing its particular characteristics. (scirp.org)
It is now widely accepted that "cortical blindness" is not an appropriate diagnostic term for children with early, acquired visual impairment due to non-ocular causes. (childrenshospital.org)
Accuracy: The expected difference in degrees of visual angle between true eye position and mean computed eye position during a fixation. (arringtonresearch.com)
Visuospatial attention can be deployed to different locations in space independently of ocular fixation, and studies have shown that event-related potential (ERP) components can effectively index whether such covert visuospatial attention is deployed to the left or right visual field. (plos.org)
Neither visual fixation of a stationary target nor large-field optokinetic stimulation substantially influenced the cycle of PAN. (mssm.edu)

Fixation of the union suture to the sclera does not improve surgical outcome. (hindawi.com)

Some of the most common causes of ocular pain include conjunctivitis, a sty, and corneal abrasions. (pursuantmedia.com)

Herpes zoster of the ophthalmic division of the trigeminal nerve, with or without ocular involvement, is referred to as HZO. (medscape.com)

Aim To assess the efficacy and safety of latanoprostene bunod (LBN) compared with latanoprost 0.005%, and to determine the optimum drug concentration(s) of LBN in reducing intraocular pressure (IOP) in subjects with open angle glaucoma or ocular hypertension. (bmj.com)

that is, different decision strategies are conceived as different concepts, with the exemplar referring to the sequence of empirical fixations on decision information during a decision process. (aisnet.org)

reported a series of 33 eyes of 26 patients underwent muscle belly union without scleral fixation [ 13 ]. (hindawi.com)
These studies have largely ignored the role of precursor fixations-previous fixations on locations the eyes return to later. (lu.se)

Leo and del Monte reported a single case report in which the myopexy was performed together with medial and inferior rectus recession and 3-point scleral fixation [ 11 ]. (hindawi.com)
In other words, the initial net force in the direction of the inferior rectus muscle would transiently extort the ocular globe. (arvojournals.org)

When CVI is suspected, fixation and following - even to intense stimulation - may be poor, and the child will not respond normally to people's faces. (childrenshospital.org)

Know and understand the risks of anterior chamber IOLs and intrascleral fixation of IOLs. (dhaj7-cepo.com)

En face OCT reflectance images which accompany OCTA studies offer a glimpse of the macrophage-like cellular activity above the retinal surface which responds to systemically instigated vascular events below. (stanford.edu)
Future studies should differentiate these parameters when evaluating adaptation of the ocular motor system. (uwaterloo.ca)

This process would mark precursor fixations as a special category of fixations, that is, distinct in neural activity from other fixation categories such as refixations and fixations to locations visited only once. (lu.se)

Sustained fixation results in the adaptation of these ocular motor systems and has been widely investigated in adults but not in children. (uwaterloo.ca)
Despite these uncertainties, the CD4 + cell count has remained the predicting parameter for the occurrence of specific ocular infection in patients who are HIV positive, at least until antigen-specific tests of T-lymphocyte function become widely available. (medscape.com)

Osiris, is a total ocular aberrometer, and is indispensable for the correct evaluation of critical patients who have, in addition to traditional low-order defects, even more complex ocular aberrations. (csoitalia.it)
Thus, whether a reconstituted T-cell count will serve as a better predictor of specific ocular infection is under active evaluation. (medscape.com)

LBN exhibited potent and effective IOP-lowering activity in three ocular hypertensive glaucoma animal models. (bmj.com)

An examination of visits to the pediatric emergency departments for emergent, urgent and non-urgent ocular conditions. (upenn.edu)

The spatial organization of orientation tuning and ocular dominance in this area provides an excellent opportunity to study this question, because orientation tuning is organized at a scale around one order of magnitude finer than the size of ocular dominance columns. (frontiersin.org)

reported two cases, one treated with traditional scleral fixation and the other with silicon band without scleral fixation [ 8 ]. (hindawi.com)
reported five cases of myopexy of the superior and lateral rectus without scleral fixation or medial rectus recession [ 12 ]. (hindawi.com)

Surgical techniques and outcomes in terms of ocular alignment are analyzed. (hindawi.com)

Anatomy51

Organisms5

Diseases85

Chemicals and Drugs16

Analytical, Diagnostic and Therapeutic Techniques and Equipment62

Psychiatry and Psychology10

Phenomena and Processes31

Technology, Industry, Agriculture2

Information Science2

Health Care5

Movements10

Saccades6

Vestibulo-Ocular2

Strabismus5

Binocular6

Torsion3

Measure ocular1

Nystagmus3

Muscular dystrophy1

Lesions2

Suppression3

Convergence1

Spatial Resolution1

Duration2

Rotation2

Retrospective1

Posterior1

Manifestations1

Myopic1

Lenses1

Deviation1

Signals3

Discomfort3

Behavior2

Vergence2

Amplitude4

Infections1

Predictive1

Muscles1

Measurement4

Trauma2

Syndrome1

Methods2

Visual7

Sclera1

Corneal1

Ophthalmic1

Subjects1

Sequence1

Eyes2

Inferior2

Stimulation1

Anterior1

Studies2

Locations1

Widely2

Evaluation2

Activity1

Conditions1

Study1

Cases2

Techniques1