• Journal of Korean Ophthalmic Optics Society
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• v.21 no.1
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• pp.53-59
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• 2016

Purpose: To investigate an individual phoria compensating effect by measuring the lens adaptation after wearing horizontal prism or spherical lenses at near. Methods: 103 subjects (63 males and 40 females) aged $22.43{\pm}2.07years$ participated for this study. Refractive errors of subjects were fully corrected, and subjects were classified into three groups; esophoria, orthophoria and exophoria. The adaptation test of prism and spherical lenses was performed immediately, 15 minutes and 30 minutes after wearing lenses with $OU\;2\;{\Delta}\;BO$ and S+1.00 D for an esophoria group and $OU\;2\;{\Delta}\;BI$ and S-1.00 D for orthophoria and exophoria groups, respectively. Each measured phoria was compared to phoria measured with fully corrected condition, and the phoria changing effects about both lenses was analyzed. Results: The mean of phoria by prism lenses significantly decreased for every group. The mean of phoria by spherical lenses also significantly decreased in orthophoria and exophoria groups. The esophoria group showed a decreasing tendency but has no significance. The decreased phoria value by prism lens was classified into three steps; 90~100%, 0~10% and 50% or more. According to results of individual distribution ratio, it was 5, 64 and 24 subjects at 30 minutes after wearing lenses, respectively. The decreased phoria value by spherical lens was classified into three steps; 90~100%, 0~10% and 50% or more. According to results of individual distribution ratio, it was 37, 53 and 41 subjects at 30 minutes after wearing lenses, respectively. The subjects having no phoria changed by both prism and spherical lenses were 37.9%. Conclusions: When prescribing to compensate the near horizontal phoria using prism or spherical lens, the pretest for lens adaptation should be taken before prescription.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.2
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• pp.137-144
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• 2010

Purpose: This study was to evaluate the clinical performance of 1-Day disposable toric soft contact lenses (TSCL) and to compare the visual performance with glasses and TSCL. Methods: In a two-week investigation of 'prism ballast' designed TSCL, occular refractions in 15 (30 eyes) healthy subjects were within the range of -2.75 D TO -8.00 D spherical power and -0.75 DC to -2.25 DC cylinderical power (with-the-rule). Subjects were assessed the clinical performance (orientation, centration, movement, tightness, rotation recovery, symptoms) of TSCL and compared binocular vision and contrast sensitivity with corrected glasses and TSCL at initial and two-week follow-up visits. Results: The prism-ballast design TSCL achieved better orientation, rotation recovery and symptoms over 2 week period. There was no statistically significant difference between spectacles and TSCL with respect to measuring binocular vision and contrast sensitivity. Conclusions: The clinical performance was good with prism-ballast design toric soft contact lenses. Evaluation of binocular vision and contrast sensitivity did not show the differences between spectacles and TSCL correction. This study suggests that TSCL wearers can be achieved similar visual performance for spectacles wearers.