• Title/Summary/Keyword: Accommodative response

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Characteristics of Accommodative Lags Determined by Objective and Subjective Methods and Their Correlation (타각적 및 자각적으로 결정된 조절래그의 특성과 상관관계)

  • Yu, Dong-Sik;Kwak, Ho-Weon;Roh, Byeong-Ho;Son, Jeong-Sik
    • Journal of Korean Ophthalmic Optics Society
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    • v.20 no.3
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    • pp.333-339
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    • 2015
  • Purpose: The aim of this study was to evaluate clinical characteristics of subjective accommodative lags determined by fused cross-cylinder (subjective method), and an open-field autorefractor (objective method) under uncorrected and corrected conditions. Methods: Thirty three healthy subjects (26 males and 7 females aged $23.73{\pm}1.35$ years from 22 to 27 years) participated. Four methods were used to determine accommodative lag: (1) a subjective method with the fused cross-cylinder (FCC) under +2.00 D fogging lenses condition, (2) an objective method with the autorefractor under uncorrected condition (3) a corrected method (effective accommodative lag) using equations presented by Gwiazda et al. in objective methods, and (4) a corrected method using equations presented by Mutti et al. in objective methods. Results: The mean accommodative lags were 0.72 D for subjective method, 0.82 D for uncorrected objective method, 0.88 D for corrected method with Gwiazda's equations, and 0.78 D for corrected method with Mutti's equations. There were significant differences between the objective accommodative lags, but no significant differences between the objective and subjective accommodative lags. The effective accommodative lags showed significant correlations between phorias and refractive errors. The effective accommodative lag by Mutti's equations had a high correlation with uncorrected accommodative lags (r=0.99, p<0.001). Conclusions: The objective accommodative lag correlated with phorias and refractive errors. Especially, The effective accommodative lag using Mutti's equations may be considered for clinical availability and qualitative evaluation associated with symptoms.

A Study on the Changes of Accommodative Function in Respect to the Viewing Angle (주시각도에 따른 조절기능의 변화)

  • Lee, Hark-Jun;Kim, Jung-Hee
    • Journal of Korean Ophthalmic Optics Society
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    • v.14 no.2
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    • pp.9-14
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    • 2009
  • Purpose: The purpose of this study was to examine the relationship between the accommodative facility, blink rate and accommodative lag according to the change of angles of main viewpoint of near distance worker and study an appropriate viewing angle that mitigates asthenopia, such as headaches or eye fatigue accompanied when reading and staring at the computer or TV for a long time. Methods: Total of 27 people including 12 male university students and 15 female university students in the age of 20 to 36 with frequent near distance works, such as computers, were selected to study the accommodative facility, the blink rate and the accommodative lag in accordance with the change of viewing angles of the near distance workers. The refraction error was corrected completely and the phoropter was shifted to near distance mode to locate the near distance indication at 40 cm. The accommodative facility and the blink rate were measured for one minute at each viewing direction of $40^{\circ}$ downward, $20^{\circ}$ downward, horizontal, and $20^{\circ}$ upward directions based on the horizontal line and the accommodative lag was measured in dynamic retinoscopy using retinoscope. Results: As a result, when the main viewpoint was moved on upper direction from the $40^{\circ}$ below, the accommodative facility was reduced and the blink rate and the accommodative lag were increased so their eyes became dry and the accommodation response was reduced. Conclusions: In near distance works, the eye fatigue level can be minimized by locating a book or a computer screen $40^{\circ}$ below than the horizontal direction.

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An Empirical Encounter of Cultural Orientation and Cultivation Theory: Factors of Perception of Materialistic Realities and Dealing with Materialism of University Students in South Korea

  • Cha, Yuri;Kwon, Yeji
    • Asian Journal for Public Opinion Research
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    • v.7 no.4
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    • pp.226-250
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    • 2019
  • The purpose of this study is to explore whether the perceptions of materialistic realities of South Korean university students can be explained by individual experience and media use. We examined: 1) relative consequences of awareness of discrimination experience and amounts of time spent on genre-specific media on perceptions of materialistic realities, 2) whether cultural orientation (allocentrism, self-monitoring, and masculinity) influences explanatory factors of awareness of discrimination experience, 3) conditions of countervailing responses to materialistic reality. As a result of analyzing the online survey data of 330 university students in Seoul, the amount of time spent on the beauty or fashion genre and awareness of discrimination experience explained the perceptions of materialist reality in Korean society. Although the perceptions that affected the accommodative response did not affect countervailing response, innovativeness had an interaction effect with perceptions of materialist reality in only countervailing response. Finally, the implications of these findings were discussed.

Changes in Accommodative Function after VDT Work (VDT 작업 후의 조절기능 변화)

  • Seo, Eun-Sun
    • Journal of Korean Ophthalmic Optics Society
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    • v.17 no.3
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    • pp.285-291
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    • 2012
  • Purpose: This study was conducted to research any effect on visual function related to accommodation by VDT work. Methods: The refraction power, accommodative lag, accommodative facility, relative accommodation, amplitude of accommodation and blink rate were measured before and after VDT work for 2 hours on 48 university students (16 males and 32 females), without abnormal accommodative function and systemic and ocular disease, who had never undergone corrective eye surgery. All examinations were performed with distant refraction, and a survey was conducted on the items related to subjective symptoms of VDT syndrome. Results: After 2 hours of VDT work, refractive power increased by 0.23 D, the amount of change in accommodative lag were $0.17{\pm}0.42D$ in the right eye and $0.23{\pm}0.47D$ in the left eye (t=2.26, p=0.03). There were statistically significant differences. Both the accommodative facility and relative accommodation and amplitude of accommodation were decreased after work. However, blink rate were increased. After VDT work, 33.4% of the subjects showed subjective symptoms of asthenopia and 33.3% of them showed shoulder pain. Conclusions: As a result, the accommodative lag increased in response to the two hours of VDT work, and overall accommodative functions were decreased. In addition, as symptoms of providing visual strain, asthenopia showed the most prominent subjective symptoms.

Evaluation of Visual Responses in Viewing a 3D Image (3D 영상 시청 시 시각반응의 평가)

  • Lee, Mu-Hyuk;Son, Jeong-Sik;Kim, Jaedo;Yu, Dong-Sik
    • Journal of Korean Ophthalmic Optics Society
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    • v.17 no.2
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    • pp.165-170
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    • 2012
  • Purpose: The aim of this study was to measure and evaluate changes of visual responses in viewing a 2D and 3D (three-dimensional) image. Methods: The subjects were 44 college students aged 19 to 25 years with normal binocular vision. The visual responses measured were CA/C (convergence accommodation/convergence) ratio, convergence-induced PD(interpupillary distance), accommodative responses, perceived distance in viewing a 3D image. Results: Convergence and accommodative responses in viewing the 3D image were significantly larger (p<0.05) than in 2D. A moderate positive correction was found between CA/C ratio and accommodative response (r = 0.477, p = 0.001). It was indicated that smaller PD had larger depth perception. Convergence in viewing the 3D image was significantly larger (p<0.05) than that at cognitive distance. Conclusions: The visual fatigue may be more intense in larger CA/C ratio and smaller PD when viewing 3D images.

Comparison between Stimulus and Response AC/A Ratios for Each Phoria with Additional Spherical Power (사위별 가입렌즈에 따른 자극 AC/A비와 반응 AC/A비의 비교)

  • Lee, Se-Hee;Yu, Dong-Sik;Son, Jeong-Sik;Kwak, Ho-Weon
    • Journal of Korean Ophthalmic Optics Society
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    • v.19 no.3
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    • pp.345-351
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    • 2014
  • Purpose: The accommodative response and the near horizontal phoria were examined with additional spherical power to analyze the stimulus and response AC/A ratios that suggest reference data for the binocular vision. Methods: The open-field autorefractometer (Nvision-K 5001, Shin nippon) and modified thorington method (MIM card; Muscle Imbalance Measure card, Bernell) at 40 cm were utilized to measure the accommodative response and the near horizontal phoria for 81 persons ($20.89{\pm}1.92$ years old) with additional spherical power. The stimulus and the response AC/A ratios were calculated by gradient AC/A method. Results: The exophoria group showed the highest accommodative response ($1.92{\pm}0.26D$) at 40 cm, followed by orthophoria group and esophoria group($1.72{\pm}0.26D$ and $1.62{\pm}0.42D$, respectively) Meanwhile, the esophoria group showed the biggest ocular deviation for the near ($23.24{\Delta}$) followed by the orthophoria group and exophoria group ($19.76{\Delta}$ and $15.14{\Delta}$, respectively). The biggest difference of the stimulus and the response AC/A ratios was $1.72{\Delta}$ for the exophoria group with -2.00 D, while the one was $3.43{\Delta}$ for the esophoria group with +1.00 D. There was a significant difference between AC/A ratios for the exophoria group with -2.00 D, -1.00 D and the esophoria group with +3.00 D, +2.00D, +1.00D and -1.00D. Conclusions: The difference between stimulus and response AC/A was greater when increased minus spherical power for the exophoria group, while it was greater when increased plus spherical power for the esophoria group. Furthermore, the difference for the esophoria group was a greater than the one for the exophoria group.

Corporate Strategies for Responding to Negative Comments on Restaurant Pages on Facebook

  • Song, Ja-Hyun;Kim, Hyun-Jung
    • Culinary science and hospitality research
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    • v.22 no.6
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    • pp.61-70
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    • 2016
  • The purpose of this study is to identify the effects of a company's response strategies (response type, communication style, and response sincerity) on customer's brand attitude and purchase intentions. A fictional Facebook fan page containing 6 separate scenarios was developed based on actual customer reviews and company responses observed on Facebook restaurant fan pages. Participants were recruited from Amazon's Mechanical Turk (MTurk). A total of 202 responses were obtained; 185 responses were analyzed after deleting insufficient responses. The results of MANOVA found that an accommodative response leads customers to have a more favorable attitude towards a brand and have stronger purchasing intentions. In addition, customers who perceive the company's response to a negative review as sincere are more likely to have a positive brand attitude and purchasing intentions, as compared to those who perceive it as either insincere or neutral.

Study on Proximal Convergence/Accommodation(PC/A) Ratio by Comparison of Gradient AC/A Ratio and Calculated AC/A Ratio (Gradient AC/A비와 Calculated AC/A비의 비교에 의한 근접성 폭주비(PC/A)에 관한 연구)

  • Han, Gyeong-Ae;Sung, A-Young
    • Journal of Korean Ophthalmic Optics Society
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    • v.9 no.2
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    • pp.223-231
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    • 2004
  • In most previous studies, the assessment of accommodative convergence to accommodative stimulus (AC/A) ratio was commonly made by measuring gradient AC/A ratio. This study deals with the proximal convergence/accommodation(PC/A)ratio measured by comparing values of the gradient AC/A ratio and the calculated AC/A ratio to prevail the clinical use of the AC/A ratio. Visual acuities of All 124 subjects had been corrected to at least 1.0 with either eye through their habitual refractive correction and the MEM dynamic retinoscopy was performed to estimate their accommodative response. And then the PC/A ratio was calculated by making use of the calculated AC/A ratio and the gradient AC/A ratio. This study showed that the difference between the mean calculated AC/A ratio and the mean gradient AC/A ratio in subgroups may be attributable to proximal convergence. Consequently, further studies on proximity cues including the PC/A ratio could be helpful to prevail the clinical use of the AC/A ratio.

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The Study on Accommodation for eyes with pseudo-crystalline lenses (인공수정체안의 조절반응에 관한 연구)

  • Lee, Seok-Ju;Sung, A-Young
    • Journal of Korean Ophthalmic Optics Society
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    • v.9 no.2
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    • pp.203-209
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    • 2004
  • Physiological accommodation in aphakia has been reported 0.50D. Also, accommodation appears in pseudo-crystalline lens. However accommodation was not clear how to works in the eyes. Therefore, the purpose of this study is that accommodation has been affected to changes of axial length and corneal refractive power when the accommodative stimulus was taken 10 diopters to person who has pseudo-crystalline lens. To determine of the accommodative response of pseudo-phakic patients who had no side effects over 2 months, we have measured the axial length, corneal refractive power in 48 patients(96 eyes). When the accommodative stimulus was taken about 10 diopters, the axial length increased by $0.05{\pm}0.06mm$ and corneal refractive power increased $0.04{\pm}0.24$ diopter. The changes of axial length in the myopia was increased by $0.19{\pm}0.18D$, emmetropia was increased by $0.12{\pm}0.16D$ and hyperopia was $0.10{\pm}0.19D$. The results of measurement revealed that the mean value was increased $0.03{\pm}0.13D$ in the myopia, and increased $0.21{\pm}0.13D$ in the emmetropia, and decreased $0.02{\pm}0.34D$ in the hyperopia.

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A Study of Social Media User Response about Firms' Crisis Response Strategies (기업의 위기대응전략에 대한 소셜 미디어 이용자의 반응 연구)

  • Kim, Bora;Kim, Woohee;Jung, Yoonhyuk
    • The Journal of Bigdata
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    • v.2 no.1
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    • pp.27-39
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    • 2017
  • The importance of online communication is getting increased by the rapid growth of smartphone supply and Social Network Service (SNS) use. Catching up with the trend, firms are actively use SNS to improve brand image, promote products, and communicate with customer. On the one hand, SNS is the channel for firms' marketing activities, but on the other, it is also the channel where the events related to the firms propagate in real time. Firms are led to unexpected state of crisis, when events are quickly spread out on SNS. Then firms are assessed their image by the way they deal with the state of crisis. This paper proposes to figure out user response on SNS according to each crisis response strategies by analyzing event-related twitter data when crisis situations of firms arise. We classify crisis response strategies into response attitude, defensive and accommodative response, and response speed, fast and slow response. This paper suggests optimal crisis response strategy to firms regarding state of crisis propagated on SNS.

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