• Journal of Korean Ophthalmic Optics Society
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• v.14 no.2
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• pp.27-30
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• 2009

Purpose: Transmittance at UV-visible spectra range was measured to confirm the effect of wet/dry state of commercially available SCL on human eyes. Method: Commercially available five SCLs fabricated by different materials were selected to measure optical properties according to humidity. Results: A relatively high transmittance above about 80% in the visible spectra range of the SCLs were observed. In the UV spectra range, the wet samples showed higher transmittance than those dried except an unusual case. Conclusions: All the samples having a high optical properties in the visible spectra range exhibit a high transmittance in the UV region. Further research will be needed to develop new materials having a sharp absorption edge in the UV spectra range.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.1
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• pp.101-105
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• 2001

It was measured the transmittance and the reflectance by tie dip method using the UV cut lens' UV solution. The half point and the edge wavelength of the transmittance were wry well applied to the eqution of a dip time dependence. $$W=W_0+A_1{e}{x}{p}[-(x-x_1)/t_1]$$ The half point wavelength of the transmittance shifted from 358 nm to 408 nm and the edge wavelength moved from 340 nm to 398 nm. The more dip time had long the less intensity of main reflectance peak-380 nm was small and shifted to long wavelength regions. And the component peak of UV solution began to show in dip time-10 min.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.3
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• pp.285-291
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• 2015

Purpose: The hydrogel lenses have been functionalized with HA(Hyaluronic Acid) using two different methods: construction of an IPN(Interpenetrating Polymer Networks) and formation of CCB(Chemical Covalent Bonding). The lysozyme adsorption and physical properties such as optical transmittance and water content of the hydrogel lenses have been investigated in order to determine whether method is suitable for the application potentials in contact lens industry. Methods: HA have been added to the hydrogel lenses prepared in the Lab using the two different method, e.g. IPN and CCB. The optical transmittance was measured in the wavelength range of 300~800 nm. The water content was measured by the gravimetric method using 0.9% NaCl saline solution. The amounts of adsorbed lysozyme on the contact lenses was analyzed by HPLC after incubation for 12h in artificial tears. Results: The water content of the HA added hydrogel contact lenses was increased, and the lens made by IPN method showed higher water content than the lens made by CCB method. The optical transmittance was over 90% both before and after addition of HA. Comparing the lysozyme adsorption reduction ratio, contact lens manufactured by IPN method was 60.0%, and the lens made by CCB method was 40.4%. Conclusions: CCB method is appropriate to distribute the functional material evenly throughout the lens, whereas IPN method is effective for the case of giving the functionality on the lens surface without phase separation.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.2
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• pp.129-134
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• 2002

We obtained the UV cut-off effect of tinted CR-39 Ophthalmic lens with the respect of concentration of green, brown, blue color. First, we analyzed the UV spectrum of tinted CR-39 lens measured by Spectrophotometer and then compared the UV data by Spectrophotometer with UV data by UV tester used in an optician shop. The result obtained show that the UV cut-off effect is increased with color concentration of tinted CR-39 lens, and the transmittance of 0%~5% at 400nm by Spectrophotometer is correspondence with transmittance of 0% by UV tester.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.1
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• pp.107-110
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• 2001

In order to estimate the UV-A line's cut efficiency it lens, it was measured the light transmittance in the 320~400nm wavelength regions. We obtained the area to integrate the light transmittance of standard CR-39 and sample in the 320~400nm wavelength regions and established ${\alpha}$, ${\beta}$ of UV-A line's cut efficiency by contrast its area. We obtained the absolute cut efficiency ${\alpha}$ CR=0.59 value of CR-39 Lens, and if ${\alpha}$ was the absolute cut efficiency value of the lens to estimate UV-A cut effect, the relative cut efficiency ${\beta}$ was $1.69{\alpha}$. It was obtained the absolute and the relative UV exclusion index through each $a=(1-{\alpha}){\times}100%$, $b=(1-{\beta}){\times}100%$.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.1
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• pp.17-21
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• 2009

Purpose: To evaluate and analyze the quality of Korean prescription lenses according to international standards. Methods: We measured the refractive power, the thickness at optical center and the transmittance, and then made a comparative analysis them with foreign brand products according to international standards. Results: Most of Korean products had good qualities on the refractive power and transmittance, even if there was out of tolerance in a case of korean products. Conclusions: To ensure a higher preference of Korean products in the home and abroad marketplace, a high-powered quality control and marketing strategy are necessary to domestic lens manufacturers.

• Journal of Integrative Natural Science
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• v.8 no.1
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• pp.60-66
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• 2015

The physical and optical properties of polymers with 2-fluoroaniline and 4-fluoroaniline added, which can be used for hydrophilic ophthalmic lenses, were investigated in this study. The UV-blocking properties of 2- and 4-fluoroaniline were also investigated by measuring their UV transmissibility. 2- and 4-Fluoroaniline were used as additives for the basic combination of HEMA, 5% AA, and 1% MMA, and the materials were copolymerized with EGDMA as the cross-linking agent and AIBN as the initiator. The refractive index, water content, optical transmittance, tensile strength, and contact angle were measured to evaluate the physical properties of the produced hydrogel lens. The measured physical properties of the hydrogel contact lens produced with the copolymerized polymer showed a refractive index of 1.425-1.436; a water content of 36.95-44.65%; a visual light transmittance of 66.0-81.0%; a tensile strength of 0.138-0.281 kgf; and a contact angle of $55.02-57.87^{\circ}$. The UV transmissibility was significantly reduced, which indicates that 2-fluoroaniline and 4-fluoroaniline have UV-blocking properties. This study showed that 2- and 4-fluoroaniline are expected to be used as UV-blocking materials in hydrogel ophthalmic lenses whose physical properties, such as their refractive index and water content, do not change.

• Journal of Integrative Natural Science
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• v.11 no.2
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• pp.113-120
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• 2018

This study was planned to prepare the high strength hydrogel ophthalmic lens containing isocyanate group and nanoparticles. HDI with carbon nanoparticles were used as additives for the basic combination of HEMA, MA and MMA, and the materials were copolymerized with EGDMA as the cross-linking agent and AIBN as the initiator. The mixture was heated at $100^{\circ}C$ for an hour to produce the high performance hydrogel ophthalmic lens by cast mold method. Measurement of the physical characteristics of the produced material showed that the refractive index was in the range of 1.4027~1.4600, water content 25.21~44.01%, contact angle $54.18{\sim}72.94^{\circ}$, visible light transmittance 53.03~92.09%, and tensile strength 0.1024~0.2359 kgf and breaking strength was 0.0872~0.2825 kgf. The results showed an increase of refractive index while the decrease in water content. And also, the breaking strength was highest when the addition ratio of HDI was 5%(wt). As a result of the absorbance measurement, no significant difference was observed in all the samples, so it can be judged that the stabilization of nanoparticles in the polymer was maintained.

• Design & Manufacturing
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• v.15 no.4
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• pp.32-36
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• 2021

In this study, the cause of the decrease in transmittance of the outer lens among the causes of the decrease in the amount of light in the automobile headlamp was identified, and the improvement method was selected to determine the effect. The causes of defects that lower the transmittance of the outer lens are divided into a moisture problem and a haze problem. The moisture problem is caused by the temperature difference between the inside and the outside of the head lamp, and the haze problem occurs when the heat inside the head lamp evaporates the haze component contained in the plastic material and attaches it to the outer lens. In order to improve the haze problem that occurs in plastic raw materials, the structures of the bulb light source type headlamp and the LED chip light source type headlamp were analyzed. Among them, the housing material of the LED chip light source type headlamp, which is structurally prone to haze gas, was selected as the test target. In the mass-production injection process of the housing, the drying process was selected as a method to minimize haze gas without adding a separate production process. After extracting a sample every drying time at a constant drying temperature, the sample was put into a haze tester and the residual amount of haze gas was measured. As a result, it was confirmed that the residual amount of Haze gas in the material decreased as the drying time increased.

• Korean Journal of Materials Research
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• v.34 no.4
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• pp.194-201
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• 2024

In this study, the surfaces of two gold nanoparticles of different shapes were modified with hexadecyltrimethylammonium bromide (CTAB) and used for contact lenses. The polymer was based on 2-hydroxyethyl methacrylate (HEMA), and spherical and sea urchin-shaped gold nanoparticles were used as additives. CTAB was used to modify the surface of the sea urchin-shaped gold nanoparticles. To analyze the physical properties of the prepared contact lens, optical transmittance, refractive index, water content, contact angle, and atomic force microscope (AFM) were measured and evaluated. The results showed the nanoparticles did not significantly affect optical transmittance, refractive index, or water content of the lens, and tensile strength increased according to the ratio of the additive. The addition of the sea urchin-shaped nanoparticles resulted in lower wettability compared with the spherical nanoparticles, but somewhat superior tensile strength. In addition, it was found that the wettability of the lens was improved when the surface-modified sea urchin-shaped gold nanoparticles were added. The types of gold nanoparticles and surface modification methods used in this study are considered to have great potential for use in ophthalmic materials.