• Journal of Korean Ophthalmic Optics Society
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• v.17 no.1
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• pp.75-81
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• 2012

Purpose: The study tried to figure out accommodative changes by measuring accommodative response, appearing on the full vision correction and low vision correction, with both eyes open-view auto-refractometer (Nvision-K5001, Shin-nippon, Japan). Methods: It carried out objective and subjective refractions, targeting 79 college students (58 males and 21 females) aged between 20 and 30($21.14{\pm}2.00$), by measuring accommodative changes with fixation distance at 1.0 m for eyesight of 1.0 after full version correction. The distances of 5.0 m, 1.0 m, 0.50 m, 0.33 m and 0.25 m for eyesight of 0.8, 0.7 and 0.6 after low vision correction arbitrarily added plus lens were applied. Results: the shorter measure fixation distances were, the greater changes accommodative response showed a tendency in the state of both full vision correction and low vision correction(0.7). The state of full vision correction showed a greater change of accommodative response than that of low vision correction(0.7). Both right and left eyes showed low accommodative responses in the state of low vision correction(0.7) than that of full vision correction. As a result of analyzing accommodative response at an eyesight of 0.8, 0.7, and 0.6 after low vision correction, the poorer eyesight was the lower accommodative response. Conclusions: Low vision correction from a near distance is expected to avoid unnecessary accommodative response, make eyes relaxed and prevent accommodative function disorder.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.1
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• pp.17-22
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• 2014

Purpose: We aimed to evaluate reliability of eye exam for visual acuity as a function of distance. Methods: There were 39 patients (78 eyes) who had visual acuity 1.0 or more at 5 meters. We measured refractive power of patients at each distances, 5 meters, 4 meters and 3 meters. Automatic chart (LCD-700, Hyeseong Optic. Co., Korea) used for visual acuity, skiascope (Beta 200, Heine, Germany) and auto refractometer (RK-5, Canon, Japan) used as for objective refraction. Accommodation was examined by minus lens addition methods, and Accommodative lag was examined by grid chart for reading distance. Results: Being compared to 3 meter test, Amount of corrected spherical refractive power decreased by $0.10{\pm}0.38$ D, astigmatism decreased by $0.05{\pm}0.10$ D, and axis of astigmatism rotated toward to temporal by $2.64{\pm}18.75$ degrees for right eyes, by $11.43{\pm}48.55$ degrees for left eyes in case of 5 meter test. Changes of corrected refraction and astigmatism were slightly correlated (r=-0.31, r=-0.29). Conclusions: Because corrected refraction power and amount of astigmatism decreased and axis of astigmatism tends to turn the temporal direction according to exam distance, examination distance of visual acuity should improved as to 5 meters.

• Journal of Korean Clinical Health Science
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• v.10 no.2
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• pp.1587-1593
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• 2022

Purpose. This study was to investigate the degree of refractive error that occurs depending on the measurement location of the subject when performing a refraction test using the automatic refractor. Methods. When performing the auto-refraction test, measurements were taken while increasing the distance between the forehead and the forehead rest, and the measurements were made by tilting the head clockwise and counterclockwise. Results. During the auto-refraction test, significant refractive error occurred when the forehead was not attached to the forehead support or the subject's head was turned clockwise or counterclockwise. Conclusions. When performing a refraction test using an automatic refractor, the examiner will have to pay attention to whether the subject's forehead is in close contact with the forehead rest, and whether the head is tilted.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.4
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• pp.403-410
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• 2012

Purpose: The purposes of this study are to investigate accommodative response among emmetropes, spectacle wearer and contact lens wearer, and correlation between refractive error and accommodative respons for each group. Methods: The 72 subjects(144 eyes) who do not have any ocular diseases were participate in this study. Subjects were categorized into emmetropes, spectacle wearer and contact lens wearer by refractive error using closed-field auto-refractometer. We measured dominant eye, naked/habitual visual acuity and refractive error of monocular/binocular vision of refractive error for far/near distance with open-field auto-refractometer and calculated accommodative lag. Results: There were no significant difference of accommodative lag between right and left eye dominant and non-dominant eye, monocular and binocular vision, and spectacle lens wearer and contact lens wearer, However the accommodative lag of binocular vision was severe than monocular vision at near. The lag of myopia was larger than emmetropes, and male was larger than female. Significant correlation was found between refractive error and accommodative lag in total subjects and the same result was found in emmetropes and contact lens wearer. However there were no significant correlation in the spectacle wearer. Conclusions: There were significant difference between emmetrops and myopes in terms of accommodative lag, however accommodative lag of spectacle wearer was not different with contact lens wearer in myopes. There were also significant correlation between refractive error and accommodative lag in emmetropes and contact lens wearer, but the accommodative lag of spectacle wearer was not significantly correlated with refractive error.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.3
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• pp.275-280
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• 2006

For this study, we analysed the difference of values between noncycloplegic and cycloplegic autorefraction in primary school children. We classified the elementary school one, two, three grade (8~10age) 79children(158eyes) who did not have strabismus or amblyopia. They were examined by using the Autorefractor in domestic market before and after cycloplegic. Discrepancies beyond 0.50D in spherical and cylindrical power and 20 degree in cylindrical axis were regarded as significant. The percentages of discrepancy were greater in spherical power between noncydoplegic and cycloplegic autorefraction(p<0.05). The percentages of discrepancy were not greater in cylindrical power between noncycloplegic and cycloplegic autorefraction. The percentages of discrepancy were greater in cylindrical axis between noncydoplegic and cycloplegic autorefraction(p<0.05). In conclusion, for the primary school children who did not wear glasses, the prediction table of this study will be helpful to reduce the test error in visual acuity and refractive error tests.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.3
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• pp.271-277
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• 2013

Purpose: The purpose was to study the corneal refractive power changes associated with the wearing of everted silicone hydrogel soft lenses. Methods: The corneal refractive power and corneal astigmatism were measured using corneal topographer (CT-1000, Shin-nippon Co., Japan) for checking change of corneal refractive power and objective refractive error was measured by auto-refractometer (Natural vision-K 5001, Shin-nippon Co., Japan). We measured at baseline and 1 week after lens wearing. Results: The correcting of corneal refractive power could be effective in low myopia. It's more effective to the higher power of greatest meridian of cornea and the more corneal astigmatism. 73% of subjects' refractive error was decrease less than 1 D and 17% of the subjects had an reverse effect (increase) occurs. The reduction of objective refractive error was more effective when cornea refractive power was great or corneal astigmatism was much. Conclusions: Pressure which the everted silicone hydrogel lens to the cornea could be caused. It occurred as the degrees of corneal power, corneal astigmatism and objective refractive error differences. Selection of an appropriate subject is important considering difficulty of changing the parameters of the lens.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.2
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• pp.61-65
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• 2002

This study examines how the average presbyopic additions and eye refraction state of old ages in city may be different to that island. There were 677 of the old who were 50 or over 90 in the sample. The visual acuity test was done by objective and subjective methods and used for near-chart program. The far-point refraction state and power of the additions lens results were as follows ; 1. Of far-point refraction state in city peoples; male: emmetropia 10%, myopia 17%, hyperopia 19%, mixed astigmatism 38%, etc. 16% female : emmetropia 20%, myopia 20%, hyperopia 20%, mixed astigmatism 27%, etc. 13% 2. Of far-point refraction state in island villages ; male : emmetropia 13%, myopia 17%, hyperopia 22%, mixed astigmatism 40%, etc. 8% female : emmetropia 7%, myopia 13%, hyperopia 26%, mixed astigmatism 44%, etc. 10% 3. Average presbyopic additions states has been presented no discrimination ; male: 50 to 60 : +1.25 or +1.50D, 61 to 65 : +1.75 or + 2.00D, 66 to 70 : +2.25 or +2.50D 71 to 75 : +2.75 or +3.00D, 76 to 80 : +3.25 or +3.50D, over81 : +3.75D female : 50 to 60 : +1.25 or + 1.50D, 61 to 65 : +1.75 or + 2.00D, 66 to 70 : +2.25 or +2.50D 71 to 75 : +2.25 or + 2.50D, 76 to 80 : +2.75 or +3.00D, over81 : +2.75 or +3.00D 4. Under the condition of wearing lens, the average working time was 1 or 2 hour but some people used over 5 hours. 5. Generally, it has been investigated the old ages peoples has ocular diseases and cataract was the most common.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.3
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• pp.201-206
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• 2006

The purpose of this study is observed effect of cycloplegia in emmetropia with use of cycloplegia. We examined the naked visual acuity, mainfest refraction, 105eyes with emmetropia(under SE ${\pm}0.50D$, Cyl ${\pm}1.00D$) after the use of cycloplegia. We used Nidek ARK-700 autorefractometer. Sexual difference of mainfest refraction error showed in male -0.67D, female -0.92D and difference of the CR and the MR male 0.5D, female 0.81D the total mean 0.69D. The naked visual acuity were in male 0.82, female 0.74, total mean 0.77. Age comparison, difference CR and MR were total mean 0.69D and 13 years group 1.1D were the highest. The naked visual acuity were in the highest 10 years group 0.86. Effect of cycloplegia was $0.69D{\pm}0.79$ in emmetropia and visual acuity was $0.77{\pm}0.21$. The optician, it will not be able to use cycloplegia, must pay attention spectacle prescription unnecessary and over correction in condition below -0.75D MR, above 0.77 visual acuity.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.4
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• pp.419-424
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• 2012

Purpose: We were to obtain the basic data for studying kinetic visual acuity through the comparative analysis in kinetic visual acuity, visual acuity, refractive error, pupil size, and hand reaction time for college students. Methods: We had tested the kinetic visual acuity, visual acuity, refractive error and hand reaction time using the kinetic visual acuity tester (KOWA AS-4A), the hand reaction time program and auto-refractometer for thirty-nine male and same female optometry students with more than +0.1 LogMAR visual acuity in both eyes. And the results were examined gender differences of kinetic visual acuity and the factors correlation. Results: In the measured values of male, pupil size were 6.00 mm, hand reaction time 0.23 msec, refractive error -1.66 D, visual acuity -0.07, kinetic visual acuity 0.59 and pupil size 5.86 mm, hand reaction time 0.24 msec, refractive error -2.08 D, visual acuity -0.02, kinetic visual acuity 0.46 in female. It was significant difference for kinetic visual acuity values but other factors were not. The kinetic visual acuity and left visual acuity had the highest correlation, r=-0.406. The kinetic visual acuity indicated more excellent values in the case of increasing visual acuity and decreasing myopia amount. Conclusions: It was able to see that male college students were better than female for kinetic visual acuity and the visual acuity were related to kinetic visual acuity.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.3
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• pp.187-192
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• 2006

The purpose of this research was to measurement real accmmnodative response amount of emmetropia using both eyes open-view auto-refractometer. We classified 377(male 146, female 231)eyes showing good naked vision at least 1.0, with a spherical equivalent refraction of under ${\pm}0.50D$ and cylindercal refraction of under -0.75D, from 10 to 59(mean $25.8{\pm}12.4$) years into 5 groups with 10 year interval and analyzed change of the near astigmatism and accommodative response amount to distinction of age. Age comparison, total mean 1.47D, 10 years age group 1.63D, 20 years age group 1.57D, 30 years age group 1.71D, 40 years age group 0.97D, and 50 years age group 0.05D. It was no difference between 10 to 30 years age group, But it showed the decre8.se which is remarkable from above 40 years age group and it does not almost response from above 50 years age group. Sexual difference, the man appeared some highly in male(mean $26.4{\pm}12.3$ years) 1.56D m female(mean $26.4{\pm}12.3$) 1.43D. Near-astigmatism power change, mean +0.12D, 10 years age group +0.06D, 20 years age group +0.16D, 30 years age group +0.09D, 40 years age group +0.05D, and 50 years age group +0,06D. No significant difference of astigmatism powers among the an groups, but from all years age group the astigmatism power appeared more highly far-astigmatism than near-astigmatism. Near-astigmatism axis change in the far-astigmatism changes at under ${\pm}10^{\circ}$ 103 eyes, above ${\pm}10^{\circ}$ rotation clockwise direction 108 eyes, above ${\pm}10^{\circ}$ rotation counter-clockwise direction 101 eyes. It was analyzed near-astigmatism axis change.