• Korean Journal of Materials Research
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• v.32 no.4
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• pp.193-199
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• 2022

In this study, lenses are fabricated using various nanomaterials as additives to a silicone polymer made with an optimum mixing ratio and short polymerization time. In addition, PVP is added at a ratio of 1 % to investigate the physical properties according to the degree of dispersion, and the compatibility with hydrophobic silicone and the possibility of application as a functional lens material are confirmed. The main materials are SIU as a silicone monomer, DMA, a hydrophilic copolymer, EGDMA as a crosslinking agent, and 2H2M as a photoinitiator. Holmium (III) oxide, Europium (III) oxide, aluminum oxide, and PVP are used. When Holmium (III) oxide and Europium (III) oxide are added based on the Ref sample, the characteristics of the lens tend to be similar overall, and the aluminum oxide shows a tendency slightly different from the previous two oxides. This material can be used as a silicone lens material with various nano oxides and polyvinylpyrrolidone (PVP) acting as a dispersant.

• Current Optics and Photonics
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• v.6 no.2
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• pp.196-201
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• 2022

Collagen fibers tens of nanometers in size, which constitute most of the corneal volume of the human eye, are layered in a uniform direction, and adjacent fiber layers are arranged at an angle of 90° to each other. According to the results of this study, the transmittance at 45° of interlayer rotation angle is highest, and higher than that of the 90° body structure. The transmittance is examined, concerning the polarization state of the incident light; circularly polarized light case shows higher transmittance than linearly polarized. Through this, a simulation to confirm the deformed structure of collagen fibers, which show higher transmittance than the anatomical structure of the cornea, is attempted.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.1
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• pp.105-115
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• 2004

In developed and industrialized countries life expectancy has increased significantly over the past century. As a consequence, the proportion of elderly individuals in these countries has also enlarged with the resulting increased burden on health care providers. In many developing countries the problem of age related and other eye disorders has far outstripped the ability to manage them. Accordingly, the World Health Organization (WHO) has introduced an initiative: Vision 2020 - The Right to Sight, with the objective of eliminating preventable blindness by the year 2020. This paper reviews the broad range of conditions involving external and internal structures of the eye and also the effects of aging on visual functions. It is hoped that this will provide a stimulus for increased study of these disorders, improved clinical diagnosis, and an enhanced interest and role in contributing to the objectives of the WHO and the World Council of Optometry with respect to early diagnosis, prevention and management of the diseases and disorders of the eye that are more prevalent in old age.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.2
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• pp.167-170
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• 2011

Purpose: This study was tried whether expectation of astigmatism from spherical equivalent visual acuity was possible. Methods: For 54 men and women (108 eyes) corrected to emmetropia, average age of 23.3, changes of visual acuity (5m) were measured with an increasing the powers at every ${\pm}$0.25D when the (-) axis of cross cylinder is $180^{\circ}$, $90^{\circ}$, and $45^{\circ}$, respectively. Results: As the power of cross cylinder was increased, visual acuity was decreased. When the powers of cross cylinder were ${\pm}$2.50D ($180^{\circ}$ and $90^{\circ}$) and ${\pm}$2.25D ($45^{\circ}$), visual acuity was 0.05 which is the minimum measurement possible. Conclusions: The diagram on astigmatism dealing with each spherical equivalent visual acuity was able to tabulate.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.1
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• pp.87-97
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• 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.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.2
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• pp.193-196
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• 2013

Purpose: This study was investigated to find out a useful instrument instead of direct ophthalmoscope for ocular photostress recovery time (PSRT) test. Methods: The PSRT test was performed using direct ophthalmoscope, trans illuminator, pen light, and camera flash for 48 subjects (average age 22.88 years, 96 eyes) who were corrected to 0.8~1.2 of visual acuity. Results: Each mean of PSRT measured by direct ophthalmoscope, trans illuminator, pen light, and camera flash was $27.90{\pm}18.40$ sec, $23.73{\pm}12.99$ sec, $21.31{\pm}15.57$ sec, and $18.98{\pm}11.64$ sec, respectively. The difference of PSRT between the eyes corrected more than 1.0 and the other eyes corrected under 1.0 of visual acuity was not found significantly. And there was no difference between dominant eyes and nondominant eyes of PSRT. Conclusions: Though the nearest instrument to direct ophthalmoscope was trans illuminator, pen light and camera flash could be the useful instruments for PSRT test.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.3
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• pp.407-412
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• 2014

Purpose: It is investigated whether the time division system can extend the field without diplopia for people with homonymous hemianopia. Methods: The time division system was manufactured by a modified mini fan and a black cardboard. In order to verify the effectiveness of the equipment, subjects with and without the equipment took part in the experiment to bisect the space and to recognize letters. Results: Subjects with and without the equipment showed +8.91 and +18.14 degrees in the experiment to bisect the space. In the experiment reading the letters and numbers with the equipment, there were 9 percentage point increase in $4{\times}4$ charts and 15 percentage point increase in $6{\times}6$ charts. It turned out that there was a remarkable improvement for the worst group for reading the charts. Conclusions: The time division system is effective in the mobility and orientation for people with homonymous hemianopia.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.1
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• pp.1-4
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• 2008

Purpose: The aim of this research was to furnish some useful information for starting an enterprise of small optician's stores. So, We want owners who will start a new optician's stores to reduce the mistake about the commencement of an optician's stores. Methods: It used the questionnaire research for owners of 31 small optical stores located in Gyeonggi Province. Data obtained from the 23 out of 31 questionnaire research were analyzed. Results: Before they started a new optician's stores, the experience of optician was mostly 4~5 years. The percent of male (73.9%) was higher than the percent (26.1%) of female owners. The period of preparing was mostly 3~5 months. Conclusions: This research offers a reserve founder some information about starting an enterprise of small optician's store.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.4
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• pp.527-536
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• 2015

Purpose: In this paper, we have dealt with problems and improvement of korean optician system. Methods: Using the relevant material of korean optician system and international optometrist system, provides the theoretical basis of the need for regulatory changes optician. Results: The people with refractive errors are increasing, 67% of refractive error test is made from optical shop and korean optician are sufficient trained, many opticians are in charge of the refractive error test at the ophthalmic hospital. We have confirmed that current law does not reflect adequately the nature of optician's work. Conclusions: Since current capacity of the Korean opticians and education system ready to provide health services for people, therefore an korean optician must redefine the law to fit the reality.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.4
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• pp.121-126
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• 2008

Purpose: To study the minimum diopter of spherical lens with normal binocular function in induced anisometropia by over-correction or under-correction in single eye. Methods: Stereoacuity of subjects without ophthalmic disease history in their twenties was measured by using Titmus-fly stereotest at 40 cm after overcorrection or under-correction in non-dominant eye or dominant eye, respectively. Results: In induced anisometropia, the stereoacuity decreased with increase of the power of added spherical lens in either nondominant eye or dominant eye. And the first reduction of stereoacuity was more prominent with the addition of (+) spherical lens than (-) spherical lens. In addition, there was more strikingly decrement of stereoacuity with addition of spherical lens to dominant eye than non-dominant eye. Conclusions: In induced anisometropia, the most outstanding reduction of stereoacuity was obtained with increment of the power of added (+) spherical lens in case of non-dominant eye with full correction and dominant eye with addition of spherical lens.