• Journal of Korean Ophthalmic Optics Society
• /
• v.12 no.4
• /
• pp.119-125
• /
• 2007

The aim of the present study was to compare the contrast sensitivity of soft contact lens wearers, spectacle wearers or emmetropia. Seventy myopic eyes and thirty emmetropic eyes aged 19 to 26 years were collected. The myopic group included 48 eyes corrected with spectacle lenses and 22 eyes of them corrected with contact lenses, too: all had corrected vision acuity of 20/20 or better. Spatial contrast sensitivity was measured using the OPTEC 6500 contrast sensitivity view-in tester included the EyeView　 Functional Vision Analysis software at photopic or mesoopic condition. There was no significant difference in contrast sensitivity between spectacle lenses and emmetropes. Myopes corrected with soft contact lenses showed statistical sensitivity losses at 1.5, 12 cycle/degree spatial frequencies. In conclusion, our findings suggest that loss of contrast sensitivity in soft contact lens wearers might be interpreted as evidence for corneal disruption before corneal pathological events occur in contact lens wearers. Contrast sensitivity testing appears to be a useful method for evaluating soft contact lenses.

• Journal of Korean Ophthalmic Optics Society
• /
• v.14 no.1
• /
• pp.39-45
• /
• 2009

Purpose: The purpose of this study is to compare the visual performance by contrast sensitivity (CS) and disability glare (DG) in low astigmatic eyes corrected with toric soft lenses and other optical corrections. Methods: Twenty university students with myopia (-1.00 to -6.50D Sph. with astigmatism up to 1.50 cyl) were enrolled and corrected by five different methods: 1) soft toric lenses; 2) spherical soft contact lenses; 3) RGP lenses; 4) best spectacle corrected visual acuity; 5) spherical equivalent spectacles. All subjects had corrected vision acuity of 20/20 or better. Contrast sensitivity and disability glare were measured using the OPTEC 6500 contrast sensitivity view-in tester included the EyeView Functional Vision Analysis software at photopic or mesopic conditions with glare. Results: At photopic condition, best corrected spectacle wearers had the highest monocular contrast sensitivity at all spatial frequency followed by soft toric lenses, RGP lenses, spherical equivalent spectacles, and spherical soft contact lenses. However, all of them were in normal contrast sensitivity value at photopic condition. At mesopic condition with glare, toric soft lenses were the highest and followed by RGP lenses, spherical equivalent spectacles, best spectacle corrected visual acuity and spherical soft contact lenses. It was observed that spherical soft contact lens wearers demonstrated lower range than normal contrast sensitivity value at mesopic condition with glare. Conclusion: Toric soft lenses gave better visual performance than spherical soft lenses in low astigmatic eyes. Subjects requiring the use of contact lenses under mesophic conditions could benefit from toric soft lenses.

• Journal of Korean Ophthalmic Optics Society
• /
• v.16 no.1
• /
• pp.51-60
• /
• 2011

Purpose: This study was to investigate visual performance and subjective satisfaction with multifocal soft contact lenses at near works in university students. Methods: In a cross-over study design, 26 students (6 male, 20 female) who did not have any ocular disorder with at least 20/20(1.0) binocular vision were fitted with singlevision lenses (SofLens$^{TM}59$, Bausch + Lomb Co. USA) or multifocal lenses (SofLens Multifocal, Bausch + Lomb Co. USA). After 2 weeks, visual performance assessments included visual acuity, stereoacuity and contrast sensitivity function at distance and near. Near point of accommodation, accommodative facility, near point of convergence, vergence facility and near range of clear vision at near were examined. Students' satisfaction and preference were measured using survey questionaries. Results: Subjects maintained at least 20/20 binocular vision with multifocal and single-vision lenses at distance and near. There was no difference between multifocal and single-vision lenses in stereoacuity, contrast sensitivity function and vergence facility at far and near. The near point of accommodation, accommodative facility, near point of convergence and the near range of clear vision with multifocal lenses were better than single-vision lenses. On the survey questionaries, subjects reported that they preferred and satisfied with multifocal lenses with near works, and single-vision lenses with distance works. Conclusions: The majority of university students preferred multifocal to single vision lenses because multifocal lenses provided better visual performance at near works. This study suggests that multifocal lens is helpful for young adult in prolonged near works.

• Journal of Korean Ophthalmic Optics Society
• /
• v.15 no.1
• /
• pp.47-53
• /
• 2010

Purpose: This study was performed to achieve an acceptable piggyback fit utilizing each subject's own GP lenses, in subjects with regular low myopic astigmatism. Methods: A randomized, prospective study of 15 subjects with the diagnosis of low myopic astigmatism was conducted. Nine subjects were female and 6 were male, and mean age was: 23.73${\pm}$1.68 years. Subjects were evaluated before participate on this study and then also evaluated with period of at two hours and two weeks after obtaining their lenses. All subjects were submitted to the following tests: measurement of comfort level by means of the analogical visual scale, best corrected visual acuity and over-refraction at distance. contrast sensitivity and stereo acuity. After evaluating the fit of plano soft lens, we applied each subject's own GP lens on top. Results: Vision, visual performance and satisfaction of piggyback contact lens system were stable, if not improved, for the 15 subjects when the data was compared to the patients' wear of rigid gas permeable contact lenses. Fit with a piggyback system had the same or improved comfort, visual acuity and contrast sensitivity compared to previous GP lens wear alone. The visual acuity, contrast sensitivity and stereo acuity did not show differences in relation to the studied lens type. Conclusions: These results suggest that it is possible to achieve a successful piggyback lens fitting utilizing a patient's own GP lens. The piggyback lens system satisfied the visual performance and visual requirements of this subject with GP lens alone for the correction of low myopic astigmatism.