• Title, Summary, Keyword: 입체 시력

Search Result 32, Processing Time 0.027 seconds

Comparison of Stereoscopic Fusional Area between People with Good and Poor Stereo Acuity (입체 시력이 양호한 사람과 불량인 사람간의 입체시 융합 가능 영역 비교)

  • Kang, Hyungoo;Hong, Hyungki
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.21 no.1
    • /
    • pp.61-68
    • /
    • 2016
  • Purpose: This study investigated differences in stereoscopic fusional area between those with good and poor stereo acuity in viewing stereoscopic displays. Methods: Stereo acuity of 39 participants (18 males and 21 females, $23.6{\pm}3.15years$) was measured with the random dot stereo butterfly method. Participants with stereo-blindness were not included. Stereoscopic fusional area was measured using stereoscopic stimulus by varying the amount of horizontal disparity in a stereoscopic 3D TV. Participants were divided into two groups of good and poor stereo acuity. Criterion for good stereo acuity was determined as less than 60 arc seconds. Measurements arising from the participants were statistically analyzed. Results: 26 participants were measured to have good stereo acuity and 13 participants poor stereo acuity. In case of the stereoscopic stimulus farther than the fixation point, threshold of horizontal disparity for those with poor stereo acuity were measured to be smaller than the threshold for those with good stereo acuity, with a statistically significant difference. On the other hand, there was no statistically significant difference between the two groups, in case of the stereoscopic stimulus nearer to the fixation point. Conclusions: In viewing stereoscopic displays, the boundary of stereoscopic fusional area for the poor stereo acuity group was smaller than the boundary of good stereo acuity group only for the range behind the display. Hence, in viewing stereoscopic displays, participants with poor stereo acuity would have more difficulty perceiving the fused image at farther distances compared to participants with good stereo acuity.

Dynamic Visual Acuity and Dynamic Stereoacuity of Athletes and Nonathletes (운동선수와 대학생 남녀의 동체 시력 및 동적 입체시에 관한 비교 연구)

  • Lee, Min-A;Oh, Jae-Man;Jung, Ju-Hyun
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.14 no.3
    • /
    • pp.43-49
    • /
    • 2009
  • Purpose: The purpose of this study was to obtain the fundamental data of dynamic visual acuity and dynamic stereoacuity. Methods: The subjects were 20 athletes (high school baseball player) and 40 nonathletes (20 male, 20 female). We assessed static visual acuity, dynamic visual acuity, static stereoacuity and dynamic stereoacuity using rotating mirror projection system and computer program. Results: Three groups had similar static visual acuity and static stereoacuity. On the other hand, the dynamic visual acuity and dynamic stereoacuity showed statistically significant differency. The mean dynamic visual acuity for athletes was 174.80${\pm}$28.70 deg/sec, 137.10${\pm}$16.54 deg/sec for male nonathletes and 111.59${\pm}$15.40 deg/sec for female nonathletes. The mean dynamic stereoacuity for athlets was 234.55${\pm}$19.64, 249.05${\pm}$8.86 for male nonathletes and 247.10${\pm}$14.89 for female nonathletes. The group of athletes had better dynamic visual acuity and dynamic stereoacuity. Conclusions: If the result of this study apply to sports, it will be very useful to improve sports performance.

  • PDF

The Development of Stereotest using Gabor Images in 3D Environment: An Explorative Study (3D 환경에서 가보 영상을 이용한 입체 시력 검사도구의 개발: 탐색적 연구)

  • Kham, Keetaek
    • Journal of Broadcast Engineering
    • /
    • v.20 no.6
    • /
    • pp.901-911
    • /
    • 2015
  • Many studies tried to develop a 3D display based stereo test as a substitute for the conventional stereo test. Although many 3D monitor based stereo tests have various advantages over the conventional stereo tests with printed stimuli, they have a crucial limitation in manipulating disparity. The least value for disparity manipulation is one pixel, which is too big to screen the normal stereo acuity in pc environment with a short viewing distance. In this explorative study, a Gabor image was employed as a test stimulus, because its position can be manipulated by changing its phase information, which allows sub-pixel manipulation for disparity. Instead of employing the methods of the conventional stereo tests where measurement was made only once for each of a wide range of disparity values, 10 replications were administrated for each of 6 disparity levels. The results from the test using Gabor images were compared with those using random dot stimulus because the latter stimulus was exactly the same as that of the conventional stereo test. The correlation coefficient between two tests was found to be moderate. After one month later, the whole test was repeated in the same settings. The correlation coefficient between test and retest results from Gabor images was found to be as high as that from a random dot stimulus, implying high test-retest reliability. These results suggest that a Gabor stimulus could be used as a test stimulus for the valid and reliable stereo test, even in the limited condition, such as 3D environment with a short viewing distance and a condition for evaluating the stereo acuity very precisely.

Changes of Dynamic Stereoacuity Depending on Distance between Rods and Rod Thickness in Three Rods Test (세막대 검사에서 막대 간 거리와 막대두께 차이에 의한 동적입체시력의 변화)

  • Han, Kyung-Do;Lee, Min-Jae;Kim, Sang-Yeob;Moon, Byeong-Yeon;Yu, Dong-Sik;Cho, Hyun Gug
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.21 no.3
    • /
    • pp.253-257
    • /
    • 2016
  • Purpose: To determine whether the distance between objects and the size of object are factors to be able to affect dynamic stereoacuity. Methods: Subjects were 37 adults (26 males and 11 females) with an average age of $23.89{\pm}1.76$. Refractive error was fully corrected for all subjects and each visual acuity of them was over 0.9. Three rods test was performed for measurement of stereoacuity. The viewing angles from left rod to right rod were set $5^{\circ}$, $10^{\circ}$, and $15^{\circ}$ and the rod thickness used 7 mm, 14 mm, and 21 mm, respectively. Stereoacuity was repeatedly measured three times in each test condition at 2.5 m distance, and reported the average value of them. Results: When rod thickness was 7 mm or 14 mm, dynamic stereoacuity decreased as the viewing angle increased, and they were significantly decreased (p<0.01) at viewing angles of $10^{\circ}$ and $15^{\circ}$ as compared with that of at $5^{\circ}$, respectively. When rod thickness was 21 mm, dynamic stereoacuity decreased as the viewing angle increased, especially, that of at $15^{\circ}$ decreased significantly (p<0.01) as compared with that of at $5^{\circ}$. The dynamic stereoacuity depending on the rod thickness have an increasing tendency as the rod thickness increased. Conclusions: The viewing angle between objects and the size of viewing object were factors that affect to dynamic stereoacuity.

Discussion on Preliminary Test for Male High School Students in Gwang-ju Area (광주지역 남자 고등학생들의 예비검사에 대한 고찰)

  • Ryu, Geun-Chang
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.12 no.4
    • /
    • pp.95-99
    • /
    • 2007
  • This study performed apreliminary test with male high school students in Gwangju metropolitan city in order to determine visual function information of high school students. For the items in this preliminary test, there were inquiry, test for long distance unaided visual acuity, pinhole visual acuity test, colour vision test, cover test and stereo test. Most complaint related to eye was about blurred vision (28.4%) and over 90% of subjects had one or more, and among them, over 50% appealed two or more complaints. 76.1% of all subjects showed less than 0.7 in unaided distance visual acuity. In pinhole visual acuity test, 98% had an improved unaided pinhole visual acuity and most of them experienced an improvement and 2% had no change or dropped. The students with normal stereoscopic vision test were 85.6% and the students under normal range were 14.4%. In colour vision test, 7.9% of them were protanomaly and deuteranomaly and none of them had trichromasy and total color blindness. In cover test, it showed 30.2% of orthophoria, 8.2% of esophoria and 61.5% of exophoria, and none of them had strabismus.

  • PDF

Development of Stereopsis Test Program for Measurement of Awareness Ratio of Stereoscopic Images (스테레오 영상 인식률 측정을 위한 입체시 테스트 프로그램)

  • Cho, Sung-Jin;Han, Hyeon-Na;Lee, Ho-Dong;Park, Min-Chul
    • Proceedings of the Korean Society of Broadcast Engineers Conference
    • /
    • /
    • pp.329-330
    • /
    • 2011
  • 3D 영상산업이 발전해 오면서 현재 3D 영상으로 가장 많이 사용되는 것이 바로 stereoscopic 영상이다. 이러한 영상은 인간의 뇌를 속임으로써 화면에 비쳐지는 영상이 마치 화면 밖에 위치하는 것 같은 착각을 일으키게 만들어 3D영상을 인식할 수 있게 해준다. 이때 사람이 양안시를 인식하는 문제에 관한 연구는 이미 안경학에서 많은 발전을 이루어 왔지만, 현재 논의의 중점인 3D 양안시력은 평소 사람이 사용하는 양안시가 아닌 3D Display에서 비춰지는 영상을 다양한 방법으로 양쪽 눈에 다른 영상을 인식하게 함으로써 입체를 인식하게 하는 것이며, 이러한 3D 양안시력을 측정하는 방법에 대해서는 기존의 양안시력과는 다른 측정 방법을 적용하여야 한다. 따라서 이 논문에서는 이러한 3D 입체 영상에 대한 입체시를 측정하는 방법에 대하여 제안한다.

  • PDF

Visual Outcomes of Monovision Keratorefractive Surgery in Presbyopic Patients (모노비전 각막굴절교정 노안 수술 후 시기능 평가)

  • Min, Ji-Young;Lee, Koon-Ja
    • The Korean Journal of Vision Science
    • /
    • v.20 no.3
    • /
    • pp.213-226
    • /
    • 2018
  • Purpose : To assess the change of binocular visual function and visual acuity in monovision surgery patients. Methods : The subjects were 58($49.57{\pm}3.27years$) monovision patients who wear glasses and contact lens before monovision surgery. 100% and 10% contrast visual acuity, near stereoacuity, distance and near convergence fused amplitude, amplitude of accommodation were measured and visual satisfaction in the real life after surgery was evaluated using a Questionnaire. All measurements were conducted before and after 1, 3 and 6 months of surgery. The pre-operative measurements were performed with glasses or contact lenses on, and post-operative measurements were conducted in the naked eye. All measurements among groups were statistically analyzed with the SPSS 21.0. Results : Among 58 subjects, 5 subjects (10 eyes) were hyperopia, 53 subjects (106 eyes) were myopia. Binocular distance and near contrast visual acuity was decreased after surgery, especially the 10 % contrast visual acuity under mesopic condition was decreased and there was no difference according to the postoperative period. In the questionnaire survey, satisfaction of distance and near vision after surgery was getting better, and night glare was worsen compare to pre-operation, however, general satisfaction was high after surgery. The near stereoacuity and distance convergence fused amplitude were decreased, and no changes in near sensory suppression and near convergence fused amplitude, and the amplitude of accommodation was increased in binocular and non-dominant eye after monovision surgery. Conclusion : The visual acuity, near stereoacuity and distance convergence fused amplitude were decreased after monovision surgery compared to progressive glasses multifocal contact lens wear, however, visual satisfaction in real life was improved.

Clinical Evaluation on Variation of Face Form Angle of Eyewear (안경 안면각 변화에 대한 임상적 고찰)

  • Ko, Da-young;Kim, Ki-hong;Lee, Dong-Hee
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.20 no.4
    • /
    • pp.477-484
    • /
    • 2015
  • Purpose: This study was investigated to evaluate the effect of the variation of the face form angle(FFA) of spectacle frame on the visual acuity and the visual function. Methods: The visual acuity, the contrast sensitivity, the stereopsis, and the phoria were measured with the spectacle frame whose the FFA is at $5^{\circ}$ and $25^{\circ}$ and the surveys were conducted on subjective symptoms. Here, 30 adults (14 men and 16 women, average age:$25.46{\pm}3.9$), who did not have ocular diseases and were fully corrected in case of having had refractive error, were to act as experimental subjects for this measurement. Results: The visual acuity and the contrast sensitivity was decreased and the phoria was tended to increase to the esophoria direction at the FFA $25^{\circ}$ than at the FFA $5^{\circ}$. The stereopsis was significantly reduced at the FFA $25^{\circ}$ than at the FFA $5^{\circ}$. Also when the FFA was larger, the higher the degree of refractive error was, the more the increase of the subjective symptoms such as being blurred characters, being disturbed head, and having sore eyes was, which reveals a statistically significant correlation between them. Conclusions: If the FFA increases, the visual acuity, the contrast sensitivity and the stereopsis was found to decrease and the phoria to increase to the esophoria direction. Therefore it shows that the variation of the FFA of spectacle frame can influence the visual acuity and the visual function.

The Effects of Sports Vision Training on Baseball Player's Visual Performance and Baseball Records (스포츠비젼 트레이닝이 시기능 및 야구성적에 미치는 영향)

  • Lee, Min-A;Oh, Jae-Man;Jeong, Ju-Hyun
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.15 no.1
    • /
    • pp.87-97
    • /
    • 2010
  • Purpose: The purpose of this study is to investigate the effects of sports vision training on baseball player's visual performance and baseball records. Methods: All subjects were 21 males of high school baseball players, and they participated on eight weeks of sports vision training program. Pre- and post- test results were obtained for static and dynamic visual acuity, static and dynamic stereo acuity, distance and near phoria, fusional reserves, near point of convergence, contrast sensitivity, visual-reaction time. Results: Statical analysis indicated significant improvement in most of mentioned visual variables and baseball records (p<0.001). Conclusions: It can be concluded that the sports vision training program improves visual skills of baseball players, which could lead to improvement in the baseball records. Vison training will be a promotor for baseball player to enhance their performance if proper test instruments and training course is supplied.

Time-dependent Changes of Visual Acuity After Alcohol Ingestion (음주 후 시간경과에 따른 시력의 변화)

  • Kim, Sang-Yoeb;Lee, Sun Haeng;Moon, Byeong-Yeon;Yu, Dong-Sik;Cho, Hyun Gug
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.13 no.2
    • /
    • pp.59-62
    • /
    • 2008
  • Purpose: This study was designed to investigate the time-dependent changes of visual acuity after alcohol ingestion. Methods: Both the subjective and objective refraction, distant contrast sensitivity, and three needle tests were carried out at 1 and 3 hours after alcohol ingestion. Results: It was found that the degree of myoptization increased as the blood alcohol level increased in the range of average -0.25D ~ -0.35D when tested 1 and 3 hours after alcohol ingestion. Under the same test conditions the increase in blood alcohol resulted in the reduction in the function of dynamic stereopsis. However, the variation in contrast sensitivity was found to be insignificant for all spatial frequencies. Conclusions: The optician has to be well aware of the fact that alcohol could affect the visual acuity and functional tests, therefore inquiring of the alcohol ingestion prior to visual test can be necessary.

  • PDF