• Title/Summary/Keyword: Binocular Vision

Search Result 135, Processing Time 0.022 seconds

A Study on the Accommodative Astigmatism of Near Vision (근거리 주시 시 조절성 난시에 대한 연구)

  • Lee, Hark-Jun
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.16 no.3
    • /
    • pp.327-331
    • /
    • 2011
  • Purpose: The purpose of this study was an accurate grasp of the astigmatic change due to eyes accommodation on near vision and suggested problems occurring accommodative astigmatism using near glasses. Methods: 154 subjects(308eyes) from 20 to 40 years selected for this study who had many opportunity of near vision. First, far vision corrective refraction measured using the phoropter, and then both eyes opened simultaneously for maintaining the function of binocular put away dot chart 40 cm. One eye was fogging and the other eye measured near vision astigmatism axis and degrees astigmatism using cross cylinder, and then compared with far astigmatism. Results: Increased degree of astigmatism persons on near vision more than decreased or did not changed degree of astigmatism persons, which could affect visual acuity more than 0.75 diopters in 30 eyes with an increase of 9.7% of total subjects. Direct astigmatism and oblique astigmatism were increased on near vision. Astigmatic axes were rotated base in direction on both eyes and 66.9% of subjects were more than ${\pm}$5$^{\circ}$ rotation. Due to the rotation axis of astigmatism, residual astigmatism is expected to occur and expect to adversely affect the eyes. Conclusions: Long-term using the glasses without correction of increased astigmatic and rotated axis on near vision should occur new residual astigmatism and increase the asthenopia also. Considered to be taken astigmatic change on near vision during near refraction examination.

Volumetric 3D Display System Based on Rotating Dot-Matrix LEDs

  • Lin, Yuanfang;Liu, Xu;Zhang, Xiaojie;Yao, Yi;Liu, Xiangdong
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2004.08a
    • /
    • pp.440-441
    • /
    • 2004
  • A volumetric three-dimensional (3D) display system was presented, which utilizes a rotating two-dimensional (2D) display panel of light emitting diodes (LEDs) to generate more than 10 million volume pixels (voxels) within a cylindrical volume of 165 mm in height and 292 mm in diameter. Due to persistence of vision, momentarily addressed voxel information is perceived and fused into a 3D image. Important cues for depth perception, such as binocular parallax, accommodation, convergence and motion parallax are satisfied automatically and naturally, thus it is suitable for individual or group viewing, without the need for any special visual aids.

  • PDF

Interocular interactions evoked by asynchronous checkerboard pattern reversals to each eye

  • Park, Hyoung-Dong;Lee, Kyoung-Min
    • Proceedings of the Korean Society for Cognitive Science Conference
    • /
    • 2010.05a
    • /
    • pp.55-59
    • /
    • 2010
  • To examine iterocular interactions in normal subjects, we recorded EEG activity from channel O1 and O2 on 14 healthy subjects while checkerboard pattern reversals were presented to each eye with different interstimulus intervals (ISIs) ranging from 0 to 218 ms. When pattern reversals were presented asynchronously to each eye, P-1 activity evoked by each reversal was significantly suppressed compared to the activation evoked by synchronous reversals. Furthermore, when there was time delay between pattern reversals to each eye, theta (4-10 Hz) band power was also significantly decreased, whereas beta (10-30 Hz) band power was relatively preserved. Our results suggest that neural activity evoked by sustained but not yet reversed checkerboard from one eye might inhibit upcoming neural response evoked by reversed checkerboard from the other eye. Decreased P-1 activity might reflect such inhibitory interaction between two eyes. Also, decreased theta and preserved beta band power might reflect engagement of different neural circuit for binocular / monocular vision.

  • PDF

A Study on the Phoria of Korean Male and Female Adults (한국인 성인 남녀의 사위에 관한 연구)

  • Sung, Duk Yong
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.6 no.1
    • /
    • pp.59-63
    • /
    • 2001
  • Once refractive error of the eye was fully corrected. Polarization Test was used to investigate binocular vision function. As the results of phoria measurement of Korean adults for 53males and 59 females, orthophoria in 27.68%, esophoria in 12.50%, exophoria in 48.21%, verical phoria in 3.75%, esophoria(+verical phoria) in 2.68%, and exophoria(+vertical phoria) in 5.36%, respectively. Horizontal phoria is below $3{\Delta}$ mostly and verical phoria is below $1{\Delta}$.

  • PDF

Vision Module to Estimate Robot's Self Moving Variation

  • Yoshiyasu Goto;Hiroshi Mizoguchi;Hidai, Ken-ichi;Takaomi Shigehara;Taketoshi Mishima
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1998.10a
    • /
    • pp.89-94
    • /
    • 1998
  • In this paper the authors propose a model about interaction of inner modules of autonomous robot which is possible to team walking action without external and explicit supervisor signal. A main feature of the model is that completed and fixed module for estimating robot's motion parameter by utilizing binocular parallax can be a supervisor for the module to team the walking action.

  • PDF

Sixth Cranial Nerve Palsy and Vertigo Caused by Vertebrobasilar Insufficiency

  • Paik, Seung Won;Yang, Hui Joon;Seo, Young Joon
    • Korean Journal of Audiology
    • /
    • v.24 no.3
    • /
    • pp.157-160
    • /
    • 2020
  • A 38-year-old woman presented with a week's history of binocular horizontal double vision and acute vertigo with gaze-induced nystagmus. We considered a diagnosis of one of the six syndromes of the sixth cranial nerve and evaluated several causes. She had history of severe anemia, vitamin B12 deficiency, and hypertension. Magnetic resonance imaging with angiography showed stenosis of the right vertebral artery and hyperintensity on both basal ganglia. As we describe here, we should consider vertebrobasilar insufficiency as a cause for sixth cranial nerve palsy if a patient has high risk for microvascular ischemia, even in the absence of acute brain hemorrhage or infarction.

Sixth Cranial Nerve Palsy and Vertigo Caused by Vertebrobasilar Insufficiency

  • Paik, Seung Won;Yang, Hui Joon;Seo, Young Joon
    • Journal of Audiology & Otology
    • /
    • v.24 no.3
    • /
    • pp.157-160
    • /
    • 2020
  • A 38-year-old woman presented with a week's history of binocular horizontal double vision and acute vertigo with gaze-induced nystagmus. We considered a diagnosis of one of the six syndromes of the sixth cranial nerve and evaluated several causes. She had history of severe anemia, vitamin B12 deficiency, and hypertension. Magnetic resonance imaging with angiography showed stenosis of the right vertebral artery and hyperintensity on both basal ganglia. As we describe here, we should consider vertebrobasilar insufficiency as a cause for sixth cranial nerve palsy if a patient has high risk for microvascular ischemia, even in the absence of acute brain hemorrhage or infarction.

The Relationship Fixation Disparity between Associated Phoria (주시시차와 각비정시의 관계)

  • Kim, Hyun-Il
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.9 no.1
    • /
    • pp.93-104
    • /
    • 2004
  • In order to have a comfortable vision without any asthenopia in work place, it is very necessary to make a complete binocular correction in addition to the perfect correction of refractive deficits. For this, At first, the exact understanding of the required corrective value of the existing angular ametropia(associated phoria) is needed. The fact likely seems fact that a correction of refractive deficits could not to be reached with single optotype, the corrections of angular ametropia(associated phoria) with single optotype is impossible. The reason is that a most ametropia(associated phoria) is accompanied with the fixation disparity. To make a perfect measurement of ametropia(associated phoria), at least, 3 kinds of optotype is essential. This fact could be explained by stating the fusional stimulus in the binocular refraction tests on each eye. If these types of three tests have not practical practice. The most of many cases may result in undercorrection.

  • PDF

Research on Visual Function Before and After Prescription of Vertical Prism (수직사위 교정 전·후 시기능 변화에 대한 연구)

  • Kim, So-ra;Lee, Gi-yung;Park, Hyun-ju
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.20 no.2
    • /
    • pp.229-235
    • /
    • 2015
  • Purpose: This study was undertaken to study on visual function before and after prescription of vertical prism. Methods: 80 subjects (10-30ages) who had been precribed vertical prism and 1 year after they were represcribed vertical prism. Results: Phoria (p=0.000), supra vergence (p=0.000), NPC (p=0.003), NPA (right eye) (p=0.005), NPA(left eye) (p=0.000) showed a significant change. Conclusion: Vertical prism prescription was reduced during revisit. Supra vergence, NPC, NPA(right eye), NPA(left eye) showed a significant change. Binocular Accommodative lag was not associated with vertical prism prescription and binocular vision findings.

A Novel Horizontal Disparity Estimation Algorithm Using Stereoscopic Camera Rig

  • Ramesh, Rohit;Shin, Heung-Sub;Jeong, Shin-Il;Chung, Wan-Young
    • Journal of information and communication convergence engineering
    • /
    • v.9 no.1
    • /
    • pp.83-88
    • /
    • 2011
  • Abstract. Image segmentation is always a challenging task in computer vision as well as in pattern recognition. Nowadays, this method has great importance in the field of stereo vision. The disparity information extracting from the binocular image pairs has essential relevance in the fields like Stereoscopic (3D) Imaging Systems, Virtual Reality and 3D Graphics. The term 'disparity' represents the horizontal shift between left camera image and right camera image. Till now, many methods are proposed to visualize or estimate the disparity. In this paper, we present a new technique to visualize the horizontal disparity between two stereo images based on image segmentation method. The process of comparing left camera image with right camera image is popularly known as 'Stereo-Matching'. This method is used in the field of stereo vision for many years and it has large contribution in generating depth and disparity maps. Correlation based stereo-matching are used most of the times to visualize the disparity. Although, for few stereo image pairs it is easy to estimate the horizontal disparity but in case of some other stereo images it becomes quite difficult to distinguish the disparity. Therefore, in order to visualize the horizontal disparity between any stereo image pairs in more robust way, a novel stereo-matching algorithm is proposed which is named as "Quadtree Segmentation of Pixels Disparity Estimation (QSPDE)".