• Journal of Korean Ophthalmic Optics Society
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• v.7 no.2
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• pp.169-174
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• 2002

Make Photochromic lens Photochromism estimation method, and gouge photochromic lens and investigated UV light source to apply. UV light source irradiation ago and after wavelength dependence of photo-transmittance (T%) of darkening and fading state by do optical equipment which is consisted of spectrophotometer, light source, power meter and detecter. Use relative ratio value of maximum $T%{\times}{\lambda}$ area and saturated state area in light off. Dependences estimation introduced darkening efficiency $(K_d)=(1-C_1/A_1)/t_{on}$ relationship value course fading efficiency$(K_f)=(C_2/A_2)/t_{on}$ value during Photochromism's irradiation time in Photochromic lens. Wavelength dependence of transmittance (T%) has form of $T_m+T_1{\exp}[-(x_0-t)/a]$ in Darkening course fading state. Can receive each estimation parameter value as result that apply Photochromism's estimation parameter Z, $K_d$, $K_f$ in Photochromic lens.

• Journal of Korean Ophthalmic Optics Society
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• v.8 no.2
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• pp.185-191
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• 2003

In this study, We measured transmittance and color change of various photochromic lens as a function of temperature(6, 12, $28^{\circ}C$), irradiation time of UVA lamp and the types of materials(plastic and glass) and distribution of photochromic ingredients(coated and bulk type). The coated-type photochromic lens showed higher saturated value than bulk-type lens without regard to temperature. And darkening rate of smoke color lenses were higher compare to brown lens in case of glass photochromic lens. All of photochromic lens passed ANSI Z80.3 regulation in transmittance and color independent of temperature. The saturated values of plastic photochromic lens excluded coated-type and glass photochromic lens were ranked as cosmetic use. The saturated value of coated-type. Tbr and TMs were general applications in $6^{\circ}C$ and $12^{\circ}C$, but cosmetic purpose in $28^{\circ}C$. The darkening rate was increased with decreasing temperature, whereas the fading rate became higher with increasing temperature.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.7
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• pp.1635-1641
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• 2009

In this study, we have prepared plastic lenses with both photochromic and hard properties by hard coating, and evaluated their optical properties and surface characteristics. Photochromic effects could be observed on the UV spectra of the closed forms and the visible spectra of the open forms. Visible light transmittance of photochromic lenses was from 83.44% for graphite(GP) to 85.15% for blue(BL) in colourless state and from 71.10% for red(RE) to 79.98% for yellow(YE) in colour state. Red photochromic lens was higher in optical density(${\Delta}$OD) and color difference(${\Delta}$$E^{\ast}_\;{ab}$) than the others. Photochromic lenses applied by hard coating showed good adhesion, hot water resistance, chemical resistance and surface appearance. Also, compared to the uncoated lens, hardness and abrasion resistance were increased. Consequently, this coating system could impart functional properties such as photochromic and hard coating property onto ophthalmic lenses.

• 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 Integrative Natural Science
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• v.11 no.1
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• pp.39-43
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• 2018

Poly(hydroxyethyl methacrylate)-based hydrogels were surface-functionalized with spiropyran (SP) derivatives to obtain photochromic contact lenses. The contact lens reversibly changes from colorless to purple as response to UV light since colorless ring-closed SP state converts to purple ring-opened merocyanine (MC) state under UV light irradiation. The purple contact lens emits red light at 640 nm. Importantly, the presence of SP segments did not significantly affect the equilibrium water content (EWC) of the lens. SP-functionalized hydrogel lenses may find potential applications in developing light-adaptive ophthalmic materials.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.1
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• pp.27-34
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• 2005

Photochromic lens is the color changing lens from colorlessness to colorness when exposed to UV light. It can protect eyes from UV-B light which cause the cataract and can be used as sunglass in the summer since it can cut off 70~80% of sun light. Surface coating technique was used to develop lens which has 70% light transmittance and of which fading time of color change is within 5 min. Various color lenses were developed so that these had various color such as blue, green, brown, violet, yellow and red etc. Lens has an excellent physical properties, 100% adhesion and 4~5H hardness. The chemical and the scratch resistance of this lens were the greatest and the thermal stability was also higher. The clinical trial of developed lens were applied to 65 patients who had photophobia by various reasons at ophthalmology of Soonchunhyang University Hospital. Results showed that glaring was significantly reduced and the visual health were remarkably improved. Especially, anti-glaring effect in the night was great for the patient who had the LASIK operation. Protection of UV-B and blue light also can prevent the patient from cataract and the yellowish crystalline lens at old ages. Through the result of clinical. trial, we know that photochromic lens could be a new technique for both cure and precaution of photophobia.

• Journal of Korean Ophthalmic Optics Society
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• v.8 no.1
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• pp.59-64
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• 2003

To Photochoromic lens light irradiation side darkening status and fading status photo-transmittance decrease. If remove light irradiation, get into fading state and photo-transmittance has reversibility process that get back originally in state. Get CIE $L^*a^*b^*$ relationship colorimetric using darkening in Photochoromic lens and at fading process. Photochromism's spectrophotometer that produce itself. Darkening and fading state colorimetric ($a^*-b^*$) linear be curvy, and is gradidnt of (-) value. And change lineally. The colorimetric transfer amount is Blue ${\rightarrow}$ Yellow, Red ${\rightarrow}$ Green form. Colorimetric is low $b^*$ value than darkning state in fading state, and Photochromism's coodination transfer moves on the contrary with darkning state, photochoromism relationship estimation method about photochoromic lens can use by colorimetric difference about darkening and fading.

• Journal of the Korean Graphic Arts Communication Society
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• v.10 no.1
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• pp.1-13
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• 1992

The recent results concerning the synthesis and application of spiroxazine dyes have been summerized., The absorption bands of usual spiroxazine dyes are changed from colorless to colored from by irradiation of ultraviolet ray. This mechanism is derived from the cleavage of oxazine ring. Such properties are dependent on its chemical structure and surrounded matrix of spiroxazine dyes. the chemical structure of this dye is similar to the well known spriopyran. But spiroxazine dyes have noticed recently, because of excellent high light-sensitivity and superior fatigue-resistant property. This dye are already applied as photochromic lens, cloths and UV light checker.