• Journal of Korean Ophthalmic Optics Society
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• v.6 no.2
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• pp.17-21
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• 2001

We analyzed the luminance in the visual light region and the size of pupil by the luminance to estimate an UV-A line cut efficiency in the lens. The size of pupil by the luminance(L) was given by ${\Phi}=d-e{\cdot}tanh(f{\cdot}logL)$ and the transmittance efficiency value of a size of pupil was given by $T_r(r)=1-gr^2+hr^4$. We derived the absolute cut efficiency value ${\alpha}$ and the exclusion index $b=(1-{\alpha}){\times}100%$ about the UV-A in the $320{\sim}400nm$ regions. The ${\alpha}$ and b values were obtained respectively 0.018, 0.31, 0.273, 0.153 and 98, 69, 72, 85% of Uv-cut Lens, CR-39, red color and blue color.

• Journal of the Korean Chemical Society
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• v.54 no.4
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• pp.460-464
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• 2010

We manufactured functional contact lens materials using 2-hydroxy-4-methoxy-benzophenone, titanium(VI) isopropoxide and nanogold, nanoplatinum with UV-blocking and antimicrobial effects. Contact lens was manufactured by cast mould method. The resulting mixture was copolymerized by heating at $70^{\circ}C$ for about 40 min, at $80^{\circ}C$ for about 40 min, and finally at $100^{\circ}C$ for about 40 min. The refractive index of 1.434 ~ 1.436, water content of 35.24 ~ 36.32%, and visible transmittance of 88.3 ~ 90.8% were obtained for the contact lens materials. The polymer materials satisfied the physical properties required to make the material suitable to be applied as a functional material for ophthalmological purposes.

• Journal of Sensor Science and Technology
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• v.28 no.4
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• pp.256-261
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• 2019

In this study, mid-infrared transparent zinc sulfide (ZnS) ceramics were fabricated through hydrothermal synthesis with different molar ratios of S/Zn (S/Zn = 0.8, 1.0, 1.2, 1.4, and 1.6). The ZnS ceramics were sintered at a relatively low temperature of $850^{\circ}C$ to prevent the occurrence of the hexagonal phase featuring optical anisotropy. The phase composition, microstructure, and optical properties of the ZnS ceramics were subsequently investigated by employing X-ray diffraction, scanning electron microscopy, and Fouriertransform infrared spectroscopy. The results obtained indicate that the ZnS nanoparticles feature the cubic phase, without the hexagonal phase. Moreover, with increasing S, the crystallinity and particle size of the ZnS nanoparticles increased. The crystallinity and density of the ZnS ceramics improved when the molar ratio of S was higher than the molar ratio of Zn, thereby enhancing the transmittance. Furthermore, the ZnS ceramic with an S/Zn value of 1.2 was found to exhibit the highest transmittance of approximately 69% owing to the reduced occurrence of the hexagonal phase and a high density of 99.8%.

• Journal of the Korean Chemical Society
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• v.55 no.1
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• pp.98-103
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• 2011

This study was done for the preparation of macromolecular material with UV-blocking features by adding the benzophenone group that is commonly used as a UV-absorbent and $TiO_2$ which is known to be a very stable material in chemical and physical aspects. Also, we compared the level of UV absorbency of the polymer produced from polymerization with previous materials and measured basic properties such as water content, refractive index and optical transmittance of produced contact lenses. The results of the measurement showed that the refractive index and water content of the contact lens with added UV-absorbent was 1.430~1.440 and 35.0~45.0% respectively, which was similar to that of previous contact lenses. Also, for optical transmittances of each wave length, contact lenses without the UV-absorbent was 89%, 88% and 89% respectively for UV-A, UV-B and visible light, indicating that the UV transmittance is very high though contrary with cases of contact lenses with added 2-hydroxy-4-methoxy-benzophenone and 2,4-dihydroxy-benzophenone which showed transmittances of 0% and 6% respectively for UV-A and UV-B showing a UV-blocking effect. Meanwhile, contact lenses with added $TiO_2$ showed transmittance of 6% and 51% respectively for UV-A and UV-B also showing a UV-blocking effect. The visible transmittance was 77~89% showing that it satisfies the visible transmittance required for ophthalmological materials.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.1
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• pp.59-63
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• 2008

Purpose: Ti thin films were deposited on slide glass and CR-39 lenses using small magnetron sputtering apparatus to of Ti thin films. Methods: The thickness of Ti thin films were measured by cross section SEM, the transmittance and reflectance of them were obtained using spectrophotometer, the refractive index and extinction of them were obtained from VASE data. Results: The transmittances of Ti thin films with 60 nm, 120 nm, 140 nm thickness were a little change within the visual region from 400 nm to 750 nm, but were increased a little amount at near 400 nm. The transmittance of 60 nm, 120 nm, 140 nm Ti thickness in d-line was 30%, 25%, 20%, respectively. Also, it was shown that the refractive indices and extinction coefficients of the Ti thin films obtained from VASE were similar to those of Ti thin film offered macleod program. Conclusions: Ti films on CR-39 with these transmittances were available for sunglass lens. It was indicated that the refractive indices and extinction coefficients of the Ti thin films were decreased with the thickness of Ti thin film, for the thickness of Ti thin films was due to very thin.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.3
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• pp.465-470
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• 2006

Coating are needed on ophthalmic lenses to enhance both the mechanical durability of the relatively soft plastic surface and the optical performance of lenses. Organic-inorganic hybrid materials as molar ratio of 3-glycidoxypropyltrimethoxysilane(GPTS), methyltrimethoxysilane(MTMS) and tetraethyl orthosilicate(TEOS) were used to improve the surface characteristics and the optical properties on allyl diglycol carbonate lenses. Coating for these plastics were at $140^{\circ}C$ for 4hrs, applied using the sol-grl process flow-coating technique. The coated lens properties of transmittance, adhesion, pencil hardness, abrasion resistance, hot water resistance and chemical resistance were investigated. The optimum properties was obtained when the ratio of GPTS : MTMS : TEOS was 1:1:2, respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.9
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• pp.641-645
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• 2013

Chalcogenide glass has superior property of optical transmittance in the infrared region. Glass made using Ge-Se how many important optical applications. We have determined the composite formular of $Ge_{0.25}Se_{0.75}$ to be the GeSe chalcogenide glass composition appropriate for IR lenses. Also, the optical, thermal and physical characteristics of chalcogenide glass depended on the composition ratio. GeSe bulk sample is produced using the traditional melt-quenching method. The optical, structural, thermal and physical properties of the compound were measured by using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Differential scanning calorimeter (DSC), and Scanning electron microscope (SEM) respectively.

• Journal of the Korean Chemical Society
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• v.54 no.1
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• pp.99-104
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• 2010

Platinum nanoparticles were added to a mixture of HEMA (2-hydroxyethyl methacrylate), NVP (N-vinyl pyrrolidone) and MMA (methyl methacrylate) in a mould at various concentrations. The resulting mixture was copolymerized by heating at $70^{\circ}C$ for 40 min, $80^{\circ}C$ for 40 min, and $100^{\circ}C$ for 40 min, respectively. The physical properties of contact lens were then measured. The oxygen transmissibility of $9{\sim}15{\times}10^{-9}$ cm/s mL $O_2$/mL ${\times}$ mmHg, water content of 34.22~35.52%, refractive index of 1.432~1.435, visible transmittance of 88.3~91.2% and tensile strength of 0.141~0.152 kgf were obtained. The addition of platinum nanoparticles to the polymer allowed the contact lens to have various colors without artificial coloring agents. The polymer materials satisfied the physical properties required to produce contact lenses, making the material suitable to be applied as a functional material for ophthalmological purposes.

• Journal of the Korean Chemical Society
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• v.54 no.3
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• pp.310-316
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• 2010

Nanoparticle with antimicrobial property has been applied to various fields. This study added silver/platinum nanoparticles to HEMA (2-hydroxyethylmethacrylate), NVP (N-vinyl pyrrolidone) and MMA (methylmethacrylate) in various concentrations and copolymerized by heating at $70^{\circ}C$ for 40 minutes, $80^{\circ}C$ for 40 minutes, and finally, $100^{\circ}C$ for 40 minutes. The particle size of used nano silver and platinum was 10 ~ 20 nm respectively. Using the polymer produced through the copolymerization process, the authors have produced a contact lens and measured the physical characteristics which showed water content of 34.29 ~ 39.00%, refractive index of 1.422 ~ 1.430, visible transmittance of 78.8 ~ 92.5% and tensile strength of 0.149 ~ 0.179 kgf. The ophthalmic lens material produced using silver/platinum nanoparticles satisfied the basic physical properties required for contact lens application.

• Journal of the Korean Chemical Society
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• v.53 no.5
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• pp.542-546
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• 2009

Recently, silver has been applied to various fields due to antimicrobial property and high conductivity. We manufactured high-performance ophthalmic material containing silver which could protect eye from environmental factors. We mixed $AgNO_3$ with conventional contact lens material. And then we copolymerized at 70 ${^{\circ}C}$ for 40 minutes under water bath, and estimated antimicrobial activity and physical properties. We used solid culture and liquid culture medium for antimicrobial test. The results of contact lens containing silver showed good antibiosis. In case of physical properties, the results showed 32.35%(water content) and 88.34% (visible transmittance) for each. We judged that we made the copolymer with antimicrobial and physical properties which is suitable for conventional contact lens.