• Korean Journal of Materials Research
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• v.28 no.12
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• pp.685-690
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• 2018

In this study, a multifunctional ophthalmic lens material with an electromagnetic shielding effect, high oxygen permeability, and high water content is tested, and its applicability is evaluated. Metal oxide nanoparticles are applied to the ophthalmic lens material for vision correction to shield harmful electromagnetic waves; the pyridine group is used to improve the antibacterial effect; and silicone substituted with urethane and acrylate is employed to increase the oxygen permeability and water content. In addition, multifunctional tinted ophthalmic lens materials are studied using lens materials with an excellent antibacterial effect (2,6-difluoropyridine, 2-fluoro-4-pyridinecarboxylic acid) and functional (UV protection, high wettability) lens materials (2,4-dihydroxy benzophenone, 2-hydroxy-4-(methacryloyloxy)benzophenone). To solve problems such as air bubbles generated during the polymerization process for the manufacturing and turbidity of the lens surface, polymerization conditions in which the defect rate is minimized are determined. The results show that the polymerization temperature and time are most appropriate when they are $110^{\circ}C$ and 40 minutes, respectively. The optimum injection amount of the polymerization solution is 350 ms. The turbid phenomenon that appears in lens processing is improved by 10 to 95 % according to the test time and conditions.

• Journal of Korean Ophthalmic Optics Society
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• v.21 no.1
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• pp.1-10
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• 2016

Purpose: The study was aimed to suggest the most effective color of the tinted lenses by evaluating the effect of the prescription with tinted lenses on the visual quality of the elderly at the age of the sixty or more. Methods: The visual acuity of fifty subjects at the age of sixty or more (17 males, 33 females with the averaged age of $71.0{\pm}6.3$) were corrected to have the visual acuity at a far distance of 0.5 or more using a trial lens frame, and non-tinted, brown-tinted, and gray-tinted lenses were randomly applied on the trial frame. The minimum legibility and minimum separability were measured at a far distance in the aspect of the visual acuity and calculated as LogMAR and then, the visual acuity was compared. The stereopsis and contrast sensitivity were also estimated at a near distance in the aspect of the visual function. The participants' preference for tinted lenses and their subjective symptoms of the visual perception and the movement were further surveyed. Results: The best minimum legibility and minimum separability was shown when wearing non-tinted lenses, and brown-tinted and gray-tinted lenses were in the next. The stereopsis and the contrast sensitivity at a near distance and the visual perception was the best when wearing brown-tinted lenses. It was surveyed that the subjective discomfort was the biggest when wearing gray-tinted lenses, and brown-tinted lenses were the best in the aspect of the subjective preference. Conclusions: As the result of this study, it was revealed that the visual acuity and visual function could be improved by the use of tinted ophthalmic lenses however, its change of visual acuity and visual function was not completely correlated with the subjective satisfaction. Therefore, the appropriate color of ophthalmic lenses should be selected in accordance with the individual visual perception and the main vision lifestyle in the elderly generation. From the present study, the use of non- or brown-tinted lens and brown- or gray-tinted lens can be recommended for distance work and near work, respectively, in the elderly generation under the illumination of about 1,000 lux.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.1
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• pp.119-124
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• 2008

Purpose: To determine whether the accommodation of amplitude (AA) was changed by the color of the spectacle lens or object. Methods: AA was measured in forty subjects in their 20s when they viewed different targeton-background color combination with achromatic, gray, brown or green lens. Minus-lens procedures were used for the estimation of AA. Results: When subjects viewed the black-on-white, red-on-white and green-on-white targets, AA under tinted lens tended to be increased compared with AA under achromatic lens. Especially, the green lens significantly increased AA whatever the color of target was. Furthermore, as subjects viewed the green target, AA was the highest irrespective of the color of lens. AA was also changed depending on the color of background, so AA on the red background was lower than on the white background. On the contrary, AA on the green background was higher than on the red or white backgrounds. Of tinted lens, the gray lens increased AA the lowest, but the green lens did the highest. The number of subjects, whose AA were measured more than 9 D, reached to 12.5% with the gray lens, 21.3% with the brown lens, 22.5% with the green lens on the green background, but 5%, 6.5% and 6.5% on the red background, respectively. Conclusions: This results showed that AA varied depending on the color of spectacle lens, objects or background, and the eye fatigue could be decreased with proper color of spectacle lens accordingly.

• 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 Korean Ophthalmic Optics Society
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• v.10 no.2
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• pp.127-132
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• 2005

Beginning the use of medical order with color contact lens, recently the color contact lens wearer increases for cosmetic order in the world. The marufacture of color contact lenses was the pigment application method, the pigment inlay method, the sandwich method, the vinding method, and so on. Now in domestic, the main use of manufacture has been the binding method. In the point of the use and manufacture of the color contact lenses, the classification of color contact lenses was the tinted and the cosmetic types. However the generally coloring of color contact lenses was the stain-method and the staining was marufactured by the thin film methods.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.3
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• pp.283-291
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• 2011

Purpose: To find an empirical fitting curve to represent the relationship between the luminous transmittance and tinted time in tinted lenses using exponential decay curves. Methods: Total ninety tinted lenses were prepared with CR-39 lenses and six different colored dyes. Single, double and triple exponential decay curves were used as trial curves in order to find the empirical fitting curve. Result: The results showed that the best empirical fitting curve was triple exponential decay curves. Conclusions: We propose triple exponential decay curves as proper empirical fitting curves to represent the tinted-time dependence of the luminous transmittance in tinted lenses.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.2
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• pp.201-205
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• 2000

The colors of a tinted lens for a mixed color could be applied to a subtractive mixture's law, and the estimation of a tinted lens used the properties of optical absorptions and the color analysis. The optical absorption properties of Yellow(x)-Blue(1-x) depended on the yellow color in short wavelength below 500 nm, the absorption in the 550~650 nm wavelength regions depended on the blue color. The absorption band in the 550~650 nm wavelength regions was a peak for an ion of transition metal. The color properties of Yellow(x)-Blue(1-x) analysing by the $L^*a^*b^*$ of CIE system shifted to toward $+a^*$ decreasing x, it was formed of a pure color because of a low saturation existing in +0.6.

• Journal of Korean Ophthalmic Optics Society
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• v.8 no.1
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• pp.53-57
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• 2003

R, G, Y, B color lenses Manufactured increasing tinted time by 5 min term. CIE $L^*a^*b^*$ coordination's analysis used spectrophotometer and CIE $L^*a^*b^*$ color system. CIE $L^*a^*b^*$ coordination transfer form about tinted time being $$b^*(Y-B)={\beta}a^*+{\alpha}$$ change to do linear almost. In red case, move in $G{\rightarrow}R$, $B{\rightarrow}Y$ form tinted time increases, and Parameter ${\alpha}$, ${\beta}$ value got each -3.49 and 0.90. In green case, CIE $L^*a^*b^*$ coordination transfer form is $R{\rightarrow}G$, $B{\rightarrow}Y$ form. Got the pure green color color in 10 min's tinted time. Parameter ${\alpha}$, ${\beta}$ value got each -0.72 and -0.55. Get into pure yellow and blue color case tinted time increases. Parameter ${\alpha}$, ${\beta}$ value are 14.11 and 1.58 in yellow, and Parameter ${\alpha}$, ${\beta}$ value are -11.62 and 1.30 in blue color.

• 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.18 no.1
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• pp.19-25
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• 2013

Purpose: The degree of the pupil covered with tinted region of circle soft contact lens was determined according to the illuminant conditions in everyday life and the change of visual acuity by its covering was further investigated. Methods: The circle contact lens having the non-tinted area of 6.2 mm in the center of the lens was applied on 82 eyes in their 20s and their minimum separable visual acuity and minimum legible visual acuity were determined under the luminances of 50 and 370 lux. Results: The covering of pupil was not found when wearing circle contact lens under 370 lux, however, some pupil covering ranged from 0.40 to 1.70 mm was observed in all subjects under 50 lux. The minimum separable visual acuity and minimum legible visual acuity were significantly decreased by the wearing of circle contact lens under 50 lux and the correlation between the larger pupil size of subjects and more decrease of visual acuity was observed. Furthermore, the decrease of minimum separable visual acuity was larger than the case of minimum legible visual acuity indicating that minimum separable visual acuity was largely affected by the covering of pupil. Conclusions: The consideration is necessary for the lens wearers and the manufacturers since the wearing circle contact lens in low-light indoor or nighttime activities may affect directly visual acuity.