• Journal of Korean Ophthalmic Optics Society
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• v.18 no.3
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• pp.297-304
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• 2013

Purpose: To investigate blue light rejection and the percentage of blue light in the visible light of blue light blocking lens according to light source, and to study prescriptions for blue light blocking lens Methods: UV-VIS spectrophotometer was used for blue light rejection and the percentage of blue light in the visible light according to light source, and the percentage of blue light in solar light was used to evaluate the prescription for blue light blocking lens. Results: The blue light rejection and the percentage of blue light in the visible light of each lens were depending on light sources. Through the way to compare the percentages of blue light in the visible light passing through the lens with that in solar light, blue light blocking lenses suitable to each light source could been selected. Conclusions: In the prescription for blue light blocking lens, inquiry for user's display must be preceded. And then the percentages of blue light in the visible light passing through the lens based on that in solar light may be useful as a method of evaluating the prescription for blue light blocking lens.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.612-618
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• 2016

The aim of this study is to investigate the effects of stray light originating from the blue-light blocking lens on the quality of the image. After designing the ideal spectacle lens, anti-reflection spectacle lens without internal reflection, anti-reflection spectacle lens with internal reflection, and blue-light blocking lens with internal reflection, the light intensity distribution and stray light distribution were derived. The designed spectacle lenses are meniscus lenses with a refractive power of 0.00 D, refractive index of 1.56, and a radius of 155.15 mm. The peaks of reflectance of the 4 types of blue-light blocking lenses are in the range between 430 nm and 440 nm, and their reflectances are 5%, 10%, 15%, and 20%, respectively. According to the analysis results, as the reflectance of the blue-light blocking lens increases, the light intensity in the center of the lens decreases and the intensity of the stray light in the center-periphery and periphery of the lens increases. This trend appeared to intensify with increasing reflectance of the blue-light blocking lenses. Because the increase in the reflectance of the blue-light blocking lens degrades the quality of the image by increasing the intensity of the stray light in the center-periphery and periphery of the lens, its reflectance needs to be adjusted by varying the blue-light blocking ratio and the luminous transmittance, in order to diminish the level of visual discomfort.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.2
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• pp.135-143
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• 2014

Purpose: To evaluate the blue-light blocking ratio and luminous transmittance of blue-light blocking lenses using the blue-light hazard function as specified in international standard. Methods: In order to calculate the blue-light blocking ratio and luminous transmittance for a total of 41 blue-light blocking lenses from 8 manufacturers, UV-Vis spectrophotometer was used for measuring the spectral transmittance of wavelengths from 380 to 780 nm. Blue-light blocking ratio was calculated using blue-light hazard function as specified in ANSI Z80.3:2010 and ISO 13666(or Korean Standard KS B ISO 13666:2004). Results: The range of the blue-light blocking ratio was from 9.3 to 96.8%, the range of the transmittance from 53.5 to 92.7%, and the range of the luminous transmittance from 58.0% to 98.1%. In general the blue-light blocking lens prepared by coating tended to have a higher luminous transmittance, while those prepared by tinting a higher blue-light blocking ratio. Conclusions: The behavior of the spectral distribution of lenses showed the possibility of the performance improvement in the blue-light blocking lenses. Manufactures need to acquire their own technology that can evaluate the performance of blue-light blocking lens based in international standard.

• Journal of the Korea Convergence Society
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• v.12 no.7
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• pp.125-131
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• 2021

Blue light with strong energy is required for light-curing resin treatment, which is being used more frequently in dentistry. To reduce the risk of exposure to scattered light, we tried to use colored lenses. The tips for light curing machine and a commercially available yellow-type blue-light blocking lens and a yellow lens colored with yellow dye, which are expected to be effective in blocking blue light, were placed in a UV-Vis spectrometer device, and transmission and blocking of blue light were tested respectively. As a result, the average blue light blocking rate of the light curing machine tips was 99.49%, and the C lens with the highest color density among commercially available lenses showed a high blue light blocking rate of 99.54%. In the case of lenses tinted with yellow, the yellow tinted C lens with the highest tint concentration showed 87.57% of blue light blocking rate. It is judged that the side effects related to the eyes caused by blue light can be reduced if a yellow-type commercially available or colored lens is worn along with a light curing machine tip during resin treatment.

• 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.

• Journal of Convergence for Information Technology
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• v.8 no.1
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• pp.147-152
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• 2018

A polarizing spectacle lens having a perfect blocking of ultraviolet light and a partial blocking of blue light and having photochromic properties has been developed. It is a functional spectacle lens which can be used as a spectacle lens in the daytime, which plays a role of sunglass in a space with strong ultraviolet rays, dramatically reducing glare caused by late-night driving or reflected light. Photochromism was recovered in 0.5 second dark reaction and 3 seconds recovery time. The polarization function was about 95%. Ultraviolet rays were completely blocked and blue light was reduced by about 30%. A lens that combines photochromic and UV blocking and polarization functions is the first attempt at investigating the domestic market.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.3
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• pp.7-12
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• 2008

Purpose: To evaluate ultraviolet (UV) blocking characteristics of transparent and tinted ophthalmic lenses. Methods: The transmittance spectra of ophthalmic lenses were measured using the method suggested in ANSI Z80.1 standard. Transmittance percentage were calculated for each lens for UV (200~380 nm; UVA, UVB, UVC) and blue light portions (380~400 nm) of spectrum. Results: The results indicate that transparent plastic lenses with middle, high refractive index and tinted plastic lenses had superior UV blocking characteristics at UV radiation while UV blocker-untreated lenses such as crown glasses and CR39 did not. All except high refractive index lenses and anti-glare night vision lens was not effectively blocked blue light. Conclusions: Crown glass and CR39 lenses need to treat UV blockers to protect eyes from UV. Also, all lenes except high refractive index lenses and anti-glare night vision lens need to treat blue light blockers for protecting from blue light.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.1
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• pp.91-97
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• 2012

Purpose: This purpose of study is to investigate the effect of UV-A-blocking or brown-tinted ophthalmic lens against A2E photooxidation which known as one of the etiologies of AMD(Age-related macular degenaration). Methods: The photooxidation of A2E, synthetic product of two molecules of all-trans-retinal and ethanolamine, was induced by the exposure to blue light (420~470 nm, $94mW/cm^2$) for 3 minutes. The inhibitory effect of UVblocking or brown-tinted ophthalmic lens against A2E photooxidation was evaluated by UV absorbance and HPLC analysis of remained A2E after the exposure to blue light. Results: UV-blocking ophthalmic lens could not inhibit A2E photooxidation induced by blue light irradiation. There was no difference in A2E photooxidation in the presence of brown-tinted ophthalmic lens to block 15% of visible ray, however, those lenses blocking 55% or 86% of visible ray showed the inhibitory effect of A2E photooxidation as 9.98% and 16.55%, respectively. By HPLC analysis, the amount of residual A2E which was not blocked by any lens was $199.29{\pm}26.53{\mu}M$, however, the inhibitory effect against A2E photooxidation was shown in the presence of brown-tinted lens. The remained A2Es were $264.58{\pm}31.91{\mu}M$ and $402.93{\pm}28.68{\mu}M$ in brown-tinted lenses of 55% and 86% blocking visible ray, respectively. However, there was no inhibitory effect against A2E photooxidation in the case of UV-blocking lens by HPLC analysis. Conclusions: In this study, brown-tinted ophthalmic lens was confirmed to have the inhibitory effect against the photooxidation of A2E, a causing substance of AMD onset.