• Journal of Korean Ophthalmic Optics Society
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• v.18 no.2
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• pp.107-115
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• 2013

Purpose: This study was conducted to investigate the change of soft contact lens parameters after eyeliner deposition and compare the cleaning efficiency and the recovery rate of lens parameters by different cleaning methods. Methods: The eyeliner was deposited on three types of soft contact lenses made of different materials for 1 hour, 4 hours and 6 hours and those lenses were washed by the eyeglasses ultrasonic cleaning and by hands. The changes in visible light transmittance, diameter and surface of those lenses were compared before and after cleaning of the lens. Results: The visible light transmittance of soft contact lenses decreased along with the deposition time of eyeliner. The patterns of the eyeliner deposition on soft contact lens appeared differently depending on the physical properties of the lens material. Thus, the largest eyeliner deposition was found on narafilcon A lens. The diameters of hilafilcon B and etafilcon A lenses were decreased, however, the diameter of narafilcon A lens was increased. The cleaning efficiency of the eyeliner deposition was greater with the multipurpose solution by hands than with the eyeglasses ultrasonic cleaner. However, the recovery of lens parameters such as the lens diameter, visible light transmittance and lens surface due to the eyeliner deposition to its original state was limited. Conclusions: From these results, it is suggested to minimize eye makeup when wearing soft contact lens. Furthermore, the reduced wearing time and shorter cycle of lens replacement may be needed by considering a change of lens parameter when the repeat eye makeup is applied.

• Journal of Integrative Natural Science
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• v.9 no.1
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• pp.16-22
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• 2016

The optical and physical and characteristics of hydrogel ophthalmic lens polymerized with addition of 2,6-difluoropyridine, SiPc(silicon 2,9,16,23-tetra-tert-butyl-29H31H-phthalocyanine dihydroxide) and nanodiamond in the basic hydrogel material were evaluated. In particular, the utility of 2,6-difluoropyridine, SiPc and nanodiamond as a hydrogel ophthalmic lens material was investigated. 2,6-difluoropyridine, SiPc and nanodiamond were used as additives. And also, 2-hydroxyethyl methacrylate, acrylic acid, methyl methacrylate and a cross-linker EGDMA were copolymerized in the presence of AIBN as an initiator. The refractive index of 1.4348~1.4361, water content of 33.30~34.02%, UV-B transmittance of 4.77~67.50%, UV-A transmittance of 1.45~89.19% and visible transmittance of 32.12~92.21% were obtained. The results of hydrogel lens containing 2,6-difluoropyridine (add 5%) showed antibiosis for staphylococcus aureus. The produced copolymer is suitable for hydrogel soft ophthalmic lenses with antibiotic and anti-UV effect.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.2
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• pp.179-188
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• 2014

Purpose: The present study was aimed to investigate the cleaning efficacy of multi-purpose solutions containing different types and content of surfactants and their effect on the visible light transmittance of soft lens. Methods: Soft lenses made of different materials (etafilcon A and hilafilcon B) were deposited tear proteins by using the artificial tear and then compared the resulting cleaning efficacy and visible light transmittance after cleaning the lens with 6 types of multi-purpose solutions containing different content of surfactants. Results: The cleaning efficacy of multi-purpose solutions was variously shown as approximately 23~43% according to the active concentration of surfactants and surface tension in multi-purpose solution when etafilcon A lens cleaned with rubbing. The highest cleaning efficacy was detected when cleaned with the multi-purpose solution containing hydrogen peroxide besides surfactant however, the amount of remaining protein was still high on the lens. After washed with multi-purpose solution, the visible light transmittance of lens was in 89.8 to 90.8%. The amount of protein deposited on hilafilcon B lens was very small compared with it on etafilcon A lens even though it was incubated in artificial tears for 7 days, which showed 5~10% of protein amount in etafilcon A lens and the decrease of visible light transmittance was also not significant. In case of rubbing with multi-purpose solution, the cleaning efficacy on hilafilcon B lens was in 45.4 to 67.4% however, the order of cleaning efficacy of multi-purpose solution was different from it on etafilcon A lens. The visible light transmittance of hilafilcon B lens has been restored to the level of new lens. Conclusions: From the result, it is concluded that the appropriate multi-purpose solution should be selected according to the lens material and the amount of protein deposit on the basis of understanding surfactants and active principle for proper care of protein deposit on soft lens and the cleaning with rubbing is more efficient for lens care regardless of manufacturer's guideline.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.4
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• pp.283-289
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• 2014

A Fresnel lens is an optical component which can be used as a cost-effective, lightweight alternative to conventional continuous surface optics. Fresnel lens solar concentrators continue to fulfill a market requirement as a system component in high volume cost effective Concentrating Photovoltaic (CPV) electricity generation. The basic principles of the fresnel lens are reviewed and some practical examples are described. To investigate the performance space of the Fresnel lens, a fast simulation method which is a hybrid between raytracing and analytical computation is employed to generate a cache of simulation data. Injection molders are warming up to the idea of cycling their tool surface temperature during the molding cycle rather than keeping it constant. Heat and cool process are now also finding that raising the mold wall temperature above the resin's glass-transition or crystalline melting temperature during the filling stage and product performance in applications from automotive to packaging to optics. This paper deals with the suitability of Fresnel lenses of imaging and non-imaging designs for solar energy concentration. The concentration fresnel lens confirmed machinability and optical transmittance and roughness measure through manufactured the prototype.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.1
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• pp.69-77
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• 2014

Purpose: The functional ophthalmic lenses containing fluorine-substituted aniline group (2,4-difluoroaniline, 2,6-difluoroaniline, 3,4-difluoroaniline) were manufactured and the physical and optical characteristics of copolymerized ophthalmic lens were investigated. Methods: HEMA (2-hydroxyethylmethacrylate), NVP (N-vinyl pyrrolidone), MA (methacrylic acid), the cross-linker EGDMA (ethylene glycol dimethacrylate) and the initiator AIBN (azobisisobutyronitrile) were used as a basic combination and fluorine-substituted aniline group (2,4-difluoroaniline, 2,6-difluoroaniline, 3,4-difluoroaniline) were used as additives for preparing the hydrogel soft contact lenses. The hydrogel ophthalmic lens was manufactured by cast mould method and the ophthalmic lenses were stored in a 0.9% NaCl normal saline for 24 hrs. Results: The optical transmittance of the sample with addition 2,4-difluoroaniline showed that the UV-B(9.8~51.4%), UV-A(58.8~79.2%) and visible transmittance(87.0~90.4%). In the case of 2,6-difluoroaniline were measured the UV-B(80.2~83.2%), UV-A(85.8~86.4%), and visible transmittance(90.8~91.4%). Also, the optical transmittance of ophthalmic lens containing 3,4-difluoroaniline were measured the UV-B transmittance of 3.8~30.4%, UV-A transmittance of 47.8%~74.4% and the visible transmittance of 86.2~91.0% respectively. Conclusions: Based on the results of this study, 2,4-difluoroaniline and 3,4-difluoroaniline can be used effectively as additive for UV-blocking ophthalmic contact lenses.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.2
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• pp.37-45
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• 2007

We have measured the spectral transmittances of UV blocking soft contact lenses, regular soft contact lenses and regular RGP lenses using the method suggested in ANSI Z80.20 standard. In order to evaluate visible light transmitting and UV blocking characteristics, we have calculated transmittances by integrating over the specific spectral ranges, i.e., visible light, UVA, UVB and UVC. We found that mean transmittances of visible light for all three categories were over 90.0 % which could be considered as within acceptable range for a contact lens. The transmittance of the UVA and UVB radiation for the UV blocking soft lenses except some cases was within UVR (Ultraviolet radiation) transmittance standard. The UV blocking ability of regular soft and RGP lenses was poor as rather expected. These results will be expected to assist clinical opticians and practitioners in utilizing the transmittance characteristics about the contact lens.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.3
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• pp.237-245
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• 2011

Purpose: The present study was conducted to investigate whether certain repeated physical and/or chemical stimuli added on ophthalmic lenses might induce any changes of the functions of lens coatings. Methods: The changes in lens surface, light transmittance, foggy duration, durability of ophthalmic lenses were determined after the application of tearing-off with tape, rubbing with acetone, soaking in acetone or distilled water of ophthalmic lens (CR-39 material) as physical and/or chemical stimuli. Results: The change of ophthalmic lens surface was detected after soaking in acetone for longer than 30 minutes by observing the lens surface to figure out the functional change of hard coating. The ophthalmic lens soaked in distilled water for 180 minutes showed little functional change of anti-reflection coating as 1% by measuring light transmittance of lens. However, the function of anti-reflection coating was almost disappeared after the ophthalmic lens was soaked in acetone for 60 minutes. The foggy duration of ophthalmic lens soaked in acetone was increased by estimating foggy duration of lens. The lens coating was shown to be defected when the pre-damaged ophthalmic lenses were torn off with tape, rubbed with acetone and soaked in distilled water or acetone by observing pre-damaged lens surface to evaluate its durability. Conclusions: The careful management during ophthalmic lens dispensing or usual eyeglass wearing is needed since the change in ophthalmic lens coatings was shown by repeated physical and/or chemical stimuli.

• The Korean Journal of Vision Science
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• v.20 no.4
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• pp.413-420
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• 2018

Purpose : We present a novel method for the analysis of blue light applied by the analysis method of David L. with optical experiment and blue light by measuring the transmittance by dividing it by the refractive power in the spectacle lens made by MR8. Methods : The lenses of -8.00D, -7.00D, -6.00D, -5.00D, -4.00D, -3.00D, and 0.00D manufactured by MR8 being sold in the market, were selected. The transmittance was measured at the intervals of 5 nm from 200 to 1000 nm with UV-VIS Spectrophotometers (SolidSpec 3700), and they were in range of the blue light (380 to 500 nm) analyzed by a David L.'s analysis method. Results : All of the MR8 lenses selected for this study almost completely blocked at the UV range. A lens of -8.00D was measured as the lowest transmittance of 59.56% in the blue light area and low values were measured at the blue areas 1 and 2 according to the analysis of David L.In the infrared ray area, the transmittance of all lenses gradually decreased. The average value of the luminous transmittance was 23.67% ~ 26.33% and then gradually decreased from -4.00D. Conclusion : Applying the analysis of David L., a minimum of 41.28% and a maximum of 46.60% were measured at the blue light 1 area and a minimum of 87.30% and a maximum of 97.55% were measured at the blue light 2 area. A minimum of 86.83% and a maximum of 96.55% were measured at the blue light 3 area, and the average was 94%. The luminous transmittance of the -3.00D lens was 26.33%, which was the highest, and that -8.00D was 23.67%, which was the lowest.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.4
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• pp.49-54
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• 2015

The fabrication of a focal length-correcting lens called the F-theta lens was performed by a 3D printer. The fabricated lenses were characterized by transmittance and reflectance measurements. The optical properties of the lens, such as scattering or transmittance efficiency, were analyzed with respect to the wavelength (red, green, and blue) and the surface roughness of the lens. There was almost no shape aberration on the focus location of 0 degrees, but elliptical focus shapes were found at 1 and 2 degrees of the laser incidence angle. The developed process is expected to be used for the quick fabrication of lenses with low costs and quick turn-out. By improving the surface roughness during postprocessing, the optical properties are expected to be comparable to commercial lens quality.

• Journal of the Korea Convergence Society
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• v.12 no.7
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• pp.61-67
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• 2021

The purpose of this study was to investigate the colors of spectacle lenses that would be effective in blocking blue light among various colors so that the damage caused by blue light could be conveniently reduced even in daily life and when filling with dental light-curing resin. Each color dye of orange, brown, gray, yellow, red, and rosa was dissolved in an individual container of a spectacle lens tinting machine, and 6 uncolored spectacle lenses were immersed in a temperature of 90℃ for 1 hour to color. As a result of comparing the blue light transmittance of the colored spectacle lens and the tip for the photopolymerizer, the blue light transmittance of the orange colored lens was 0.82%, and the blue light blocking effssect was the best. Brown and gray tinted lenses had excellent blue light blocking rate, but it was difficult to recognize objects through the lens due to the high tinted concentration, and yellow tinted lenses were found to be effective when the tint was similar to the tip. The blue tinted lens had a blue light transmittance of 15.10%, which was lower than other tinted lenses. The results of the experimental study are expected to be helpful in recognizing the blue light transmittance by spectacle tinted lenses of various colors and making efforts to select the appropriate blue light blocking lens color and block harmful blue light stimuli.