• Journal of Korean Ophthalmic Optics Society
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• v.4 no.1
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• pp.57-61
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• 1999

This is a study of measurement of inter Reading Pupillary Distance (P.D.) in 729 old aged farmers (aged over 50). The average of Reading Pupillary Distance (P.D.) in man (58.93mm) is bigger than in woman (57.82mm), and the O.C. of Ready-made Reading Spectacles is 68.98mm.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.1
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• pp.109-114
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• 2009

Purpose: This study was designed to investigate the condition of refractive correction on wearing glasses currently of elementary school children and their accommodative ability in Jinju city. Methods: Objective refraction, subjective refraction, amplitude of accommodation, negative and positive accommodation, accommodative facility, and dynamic retinoscopy were examined on 60 elemenary school children who aged 8~12 wearing myopiacorrected glasses. Results: The condition of refractive corrections was distributed that a case of full correction was 11.7%, a case of low correction with more than 0.8 visual acuity (VA) was 10%, and a case of low correction with less than 0.8 VA was 78.3% in wearing glasses currently. In results from examination of accommodative ability, the number of children having accommodative anomaly is 8 persons (13.3%), they were divided into accommodation insufficiency (4 persons), accommodative facility insufficiency (2 persons), accommodation excess (1 person), and accommodation insufficiency related to ocular function (1 person). Conclusions: It is demanded a periodic inspection of refractive correction to growing children, and the refractive correction after due consideration to accommodative ability is really needed.

• Korean Journal of Optics and Photonics
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• v.19 no.6
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• pp.439-447
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• 2008

There is a need for a finite schematic presbyopic eye that models vision and image quality under various conditions such as cataract or refractive surgery, as well as near vision corrections with an ophthalmic lens or contact lens. Using recently measured biometric data of presbyopic eyes, new model eyes were designed that are optically and anatomically close to real eyes. The parameters changing significantly with age were incorporated into models for four different age groups. The new model eyes have alpha angle, decentered pupil, aspheric GRIN lens and aspheric retinal surface. It is likely that the new finite presbyopic model eyes will be useful for designing visual instruments such as low vision aids, PALs, IOL and contact lenses, and for the clinical prediction of the retinal image quality of a presbyopic patient.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.4
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• pp.255-259
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• 2005

When we wear contact lenses for correcting astigmatism, we often experience the axis-rotation of contact lenses that is happened in case we could not fit the axis of lens exactly or by the eyelid used to blink. In this case, because the exact correcting state becomes in the wrongly correcting state, the asthenopia is led, and the decline of eyesight can be led. For this reason, we need to know axis-rotating degrees of contact lenses. If a contact lens rotated, a residual astigmatism may be detected in the refraction examination after wearing. Using this, we developed a program that calculates the axis-rotating amount of contact lenses.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.3
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• pp.65-73
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• 2009

Purpose: This study was conducted to investigate the changes in distance refractive power and reading addition that occur after wearing corrective glasses for prebyopia. Methods: The subjects aged 42 to 75 years who had no ophthalmologic diseases and did not undergo cataract or retina surgery, had a corrected visual acuity of 20/20 and did not have a previous history of wearing corrective glasses for presbyopia. These subjects were divided into 3 groups: the control, reading spectacles and multifocals wearing group and they were measured for distance refractive power and reading addition at their visit. The maximum follow-up period was 73 months. Results: As for distance refractive power, the power tends to shift to hyperopia depending on age (r=0.486, p<.001) and 50.0% of the subjects increased plus power during this study period. Plus power Increments per year in distance refractive power in the reading spectacle wearing group were significantly different with control and multifocals wearing group (p<.05). On the other hand, the multifocals wearing group's increments were not different with control. Increments in reading addition were also increased in the reading spectacles group than in the control and multifocals wearing groups (p<.05). Conclusions: The age related hyperopic shift could be occurred in the elderly people, routine refraction is mandatory. And reading spectacles could induce an age related hyperopic shift and the additional need for reading addition that the prescription of multifocals may reduce changes in distance refractive power and reading addition.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.1
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• pp.73-81
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• 2000

This review on ocular toxicology concentrates on the effects on ocular health and contact lens wear induced by systemically used drugs, including alcohol. Many systemically administered drugs produce ocular adverse effects. Fortunately, relatively few are capable of causing significant, irreversible visual impairment. The visual symptoms of acute intoxication are as follows : Drop in vision/visual acuity, diplopia, poor dark adaptation, increase in time for glare recovery, early cataract, decreased depth perception, blue-yellow or red-green colour defect and visual hallucinations. Blinking pattern, tear production, and discoloration of contact lenses can be affected by some systemic or local ocular medications. The cornea, conjunctiva, or eyelids may react to some systemic medications and to some preservatives used in contact lens solutions. The hydrogel contact lens act as a drug reservoir that emits the drug over time. I discuss management of contact lens-induced infectious and inflammatory conditions.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.2
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• pp.1-12
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• 2007

Object of this research is to estimate the effect of myopia correction and safety on reverse geometry contact lens fitting in school children. This research include 53(106eyes) schoolchildren among 7 to 18 years who has low to moderate myopia(-1.00D~-5.00D) and prescribed reverse geometry contact lens for purpose on orthokeratology between January to July 2004 and had 3months full follow up examination. They were tested for slit lamp examinations, BUT(Break up time), direct ophthalmoscopy, retinoscopy, uncorrected visual acuity, best corrected visual acuity, autorefraction, autokeratometry and corneal topography in each examination(1day, 1week, 2weeks, 1, 2, and 3months) of before-and-after lens wearing to find out the effect of myopic correction and side effect. The results came out as follow. The average of uncorrected visual acuity was $0.0938{\pm}0.378$ before lens wear and $0.3136{\pm}0.283$ after 1day lens wear, and there was fast improvement after 1week($0.7925{\pm}0.301$) and little improvement after 2weeks period but still they shows better uncorrected visual acuity(p<0.01). The result of this study, the reverse geometry lens is very useful to correct refractive error and control the progression of myopia temporally among low to moderate myopic patient. The side effects were relatively rare but further study should be necessary with long term lens wear effect on eye health. For the lens prescription, the clinical fitting process had higher rate of success with consideration of eccentricity and corneal topography.

• Journal of Digital Convergence
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• v.16 no.11
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• pp.455-464
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• 2018

Recognizing the shortage of information about business models to generate profit despite the designers' recent interest in 3D printers as a new creative tool, this study set out to make sunglasses for young children, which lacked diversity in sizes according to age due to the small market scope under the old mass production system, by taking advantage of 3D printers' strength in the small batch production of customized products and propose a practical example to be expandable as a small-size business model. For these purposes, the investigator summarized the basic information about the 3D printing technology and the basic structure of sunglasses and made a size table to manufacture sunglasses for young children by analyzing the size table for vision correction. After this series of work, the study presented final product with the production costs and demonstrated that sunglasses for young children made with a 3D printer could be a practical case expandable as a competitive small-size business model in the market.

• Journal of Korean Ophthalmic Optics Society
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• v.8 no.2
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• pp.169-175
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• 2003

This research reviewed that 83 male subjects. 89 female subjects of middle and high school visited D Optical shop at the downtown of Daegu more than twice from January, 1999 to January, 2003 and obtained the following results by using the visual acuity prescription of them for which D Optical shop was keeping. 1. The classification of correction power for 190 myopia eyes was examined (87 male eyes, 103 female eyes) showed 89 eyes(46.82%) between $0.25D{\leq}3.00D$, 86 eyes(45.26%) between $3.25D{\leq}6.00D$, 15 eyes(7.89%) for over 6.25D. 2. The kind of 154 astigmatism subjects(79 male eyes, 75 female eyes) was direct astigmatism 83.77%, reverse astigmatism 11.69%, oblique astigmatism 4.55%. The cylindrical correction power for astigmatic eyes was 61 eyes(39.61%) between $0.25D{\leq}0.50D$, 60 eyes(38.96%) between 0.50D<1.00D, 121 eyes(78.57%) for less than 1.06D, 6 eyes(0.65%) for over 3.00D. 3. The variation of spherical power showed 161 eyes(46.80%) between $0.00D{\leq}0.50D$, 109 eyes(31.69%) between $0.51D{\leq}1.00D$, 17 eyes(4.94%) for over 2.01D variation. 4. The variation of astigmatic power showed 92 eyes(59.74%) between $0.00D{\leq}0.50D$, 39 eyes(25.32%) between $0.26D{\leq}0.50D$, 10eyes (6.49%) between $0.51D{\leq}0.75D$, 13 eyes(8.44 %) for over 0.76D astigmatic variation. 5. The variation of equivalent spherical power showed 137 eyes(39.83%) between $0.00D{\leq}0.50D$, 126 eyes(36.63%) between $0.51D{\leq}1.00D$, 40 eyes(11.63%) between $1.01D{\leq}1.50D$, 21 eyes(6.10%) between $1.51D{\leq}2.00D$, 20 eyes(5.81%) for over 2.01D variation.