Correlation Between Refractive Asymmetry and Eye Dominance According to the Sensory and Fixation Method

Objective: To explore the characteristics of refractive parameters and retinal and choroidal blood flow in dominant and non-dominant eyes. Methods: A cross-sectional study. Students who were 18 to 32 years old and had emmetropia or myopia but no systemic diseases were recruited from universities in Wuhu, Anhui Province from April 2019 to August 2023. They were divided into 4 groups based on the difference in spherical equivalent between two eyes:<0.50 D (group A), 0.50 to 1.74 D (group B), 1.75 to 2.49 D (group C), and≥2.50 D (group D). The card hole method was used to determine the dominant eye. The refractive parameters of both eyes were recorded, including spherical equivalent, myopia degree, astigmatism degree, axial length, and corneal curvature difference (K2-K1). Optical coherence tomography angiography was performed to measure the blood flow density of the superficial retinal capillaries, deep retinal capillaries (DVC), avascular layer (AC), entire retina, choroidal capillaries, and choroidal vessels, as well as the retina and choroid as a whole. Statistical analysis was conducted using the paired sample t-test, chi square test, and variance analysis. Results: A total of 78 eligible subjects, aged (24.50±2.36) years old, 28 males and 50 females, were included. Fifty subjects had the right eye and 28 had the left eye as the dominant eye. Forty-two subjects had high myopia in the dominant eye, and 30 had high myopia in the non-dominant eye. There were statistically significant differences (all P<0.05) in the spherical equivalent [(-4.588±2.534) D vs. (-4.058±2.453) D], myopic spherical power [(-4.253±2.504) D vs. (-3.779±2.425) D], and axial length [(25.531±1.212) mm vs. (25.256±1.238) mm] between dominant and non-dominant eyes among all subjects, as well as in the astigmatism degree of groups A and C, spherical power of groups B to D, and spherical power and axial length of groups C and D. There were also statistically significant differences (all P<0.05) in the blood flow density of the DVC [(0.291±0.130) vs. (0.257±0.148)], AC [(0.347±0.118) vs. (0.326±0.126)], and overall retina and choroid [(0.385±0.102) vs. (0.349±0.084)] between dominant and non-dominant eyes among all subjects, as well as in the blood flow density of the superficial retinal capillaries, DVC, AC, choroidal capillaries, and overall retina and choroid of groups C and D, density of the choroidal vessels of group C, and density of the entire retina of group D. Conclusions: In young individuals with emmetropia or near vision, the degree of myopia in dominant eyes is higher than that in non-dominant eyes. When the difference in the spherical equivalent between two eyes is ≥1.75 D, the blood flow density of the retina and choroid in the dominant eye is greater than that in the non-dominant eye.

To compare the accommodative amplitude (AA), facility (AF), and lag between dominant and non-dominant eyes. Seventy students [mean (SD) age: 21.2 (1.7) years, range 18-25] from Zahedan University of Medical Sciences were selected. Retinoscopy and subjective refraction was used to determine the refractive error. The hole-in-the card method was used to determine eye dominance. The accommodative amplitude (AA) was measured in the dominant and non-dominant eye using the push-up method, and accommodative facility (AF) using ±2.00 dioptre flipper lenses at 40cm. Accommodative lag was determined using monocular estimate method (MEM) retinoscopy at 40cm. The right eye was dominant in 53 subjects (75.7%). There was no significant difference in refractive error (sphere, cylinder, and spherical equivalent) between dominant and non-dominant eyes. The mean (SD) for the AA, AF, and lag in dominant eyes was 12.48 (2.56) dioptres, 12.45 (4.83) cycles per minute, and 0.80 (0.27) dioptres respectively. The mean (SD) for the AA, AF, and lag in non-dominant eyes was 12.16 (2.37) dioptres, 12.20 (4.88) cycles per minute, and 0.83 (0.28) dioptres respectively. The mean (SD) difference in AA, AF, and lag between dominant and non dominant eyes was 0.32 (0.75) dioptres (P = 0.001), 0.25 (1.05) cycles per minute (P = 0.04), and -0.02 (0.11) dioptres (P = 0.10) respectively. The AA and AF was statistically better (P < 0.05) in the dominant eye group than in the non-dominant eye group. These data provided little evidence of any difference in the accommodative lag between dominant and non-dominant eyes (P > 0.05). The right eye was dominant in 76% of subjects. Superior AA and AF was found in the dominant eye as determined by hole-in-the card method in young healthy adults, although these differences are perhaps not of clinical significance (<0.50 dioptres and <2cycles per minute).

Background: Ocular dominance is the consistent preference of using one eye over the other during visual processing, a phenomenon analogous to hand dominance. Ocular dominance often aligns with the eye delivering clearer vision, but does not always correspond to superior visual acuity or refractive status. Mechanisms underlying ocular dominance remain unclear, particularly in individuals whose refractive errors have remained uncorrected since childhood. In this study, we investigated ocular dominance patterns and their association with refractive error and handedness in individuals without early optical correction. Methods: In this cross-sectional study, we recruited individuals aged 16–40 years with refractive errors, who had no history of spectacle use since childhood, from Biratnagar Eye Hospital, Nepal. Participants underwent anterior and posterior segment examinations using slit-lamp, followed by non-cycloplegic retinoscopy and subjective refraction. Ocular dominance was assessed using the Hole-in-the-Card (Dolman’s) and Miles tests. Hand dominance was determined through standardized questioning and observation during tasks. Spherical equivalents (SEQ) were calculated, and anisometropia was defined as an interocular refractive difference equal or greater than 1.00 D. Results: Four hundred participants (mean [standard deviation, SD] age 26.1 [6.0] years; 61.3% males) were assessed for ocular and hand dominance. Refractive error SEQ ranged from +9.25 D to –13.50 D (mean [SD] –1.75 [2.46] D). Myopia was most common among students (n = 93, 23.3%) and least common among tailors (n = 14, 3.5%). The most frequent dominance pattern was right-hand combined with right-eye dominance (n = 328, 82%). A strong, statistically significant association was found between ocular and hand dominance (P &lt; 0.01; Cramer’s V= 0.73). Moderate but statistically significant associations were observed between refractive error type and both ocular (P &lt; 0.01; V = 0.25) and hand dominance (P &lt; 0.01; V = 0.21). The dominant eye was not always the eye with better visual acuity. Among the 103 individuals with anisometropia (25.8%), ocular dominance was not consistently accompanied by either the higher refractive error or better visual acuity. Conclusions: In this study, we demonstrated a strong and statistically significant association between ocular and hand dominance, suggesting existence of a significant lateralization pattern among individuals with refractive error who had no history of spectacle use since childhood. While a right-hand/right-eye dominance pattern was predominant, variations such as cross-dominance and absence of ocular dominance were also observed. A moderate but significant association was found between the type of refractive error and both ocular and hand dominance, indicating that visual and motor lateralization may influence refractive development. The dominant eye did not consistently accompany by better visual acuity or greater refractive error in individuals with anisometropia, underscoring the complexity of ocular dominance and its clinical implications. These findings may aid in understanding visual behavior and inform clinical decisions related to refractive surgeries, amblyopia management, and binocular vision assessments. Further research is needed to explore the underlying neurophysiological mechanisms.

Refractive error after penetrating keratoplasty is a major clinical problem. The purpose of the present study was to investigate whether the topography of the donor cornea influence the topography of the graft after transplantation. Twenty-five donor corneas were measured with a video-keratograph (TMS-1): in situ and before and after organ culture. Clinical video-keratographic images of the transplanted grafts were subsequently obtained one week, 1, 3, 6, 12, and 24 months after surgery. The central spherical equivalent power and corresponding regular and irregular astigmatic powers were computed. A statistically significant correlation between spherical equivalent central donor power and spherical equivalent central graft power after keratoplasty was found at all times up to two years after surgery. Only 13-50% of the variation in post-keratoplasty spherical graft power could, however, be explained by the donor graft power. Corresponding 95% confidence limits for prediction of post-keratoplasty power from donor graft power were approximately +/- 6.5 diopters. Post-keratoplasty regular or irregular corneal astigmatism did not correlate with astigmatism in the donor graft. Corneal donor graft spherical equivalent power does influence the spherical equivalent corneal power after keratoplasty, especially during the first months after surgery. The dependency is, however, not very strong and until other determinants of post-keratoplasty corneal shape are known and controllable, 'power-typing' of donor corneas appears to be of limited clinical use.

To investigate the association between ocular dominance (sighting dominance) and refractive asymmetry in phakic patients. This retrospective study included 3,012 patients with a mean age of 29.0 ± 5.3 years (range: 20 to 39 years). Refractive error was determined with cycloplegic refraction and axial length was determined with IOLMaster (Carl Zeiss Meditec, Dublin, CA). Ocular dominance was assessed using the hole-in-the-card test. The right and left eyes were dominant in 77.7% and 22.3% of the patients, respectively. In the high anisometropia group (⩾ 2.0 diopters), the non-dominant eyes had significantly higher myopic spherical equivalents and longer axial lengths than the dominant eyes (P < .05). However, there were no significant differences in these parameters in the low anisometropia group. The current study revealed that non-dominant eyes had a greater myopic refractive error and longer axial length than the dominant eyes, especially in the patients who had high amounts of anisometropia.

Objective: To investigate the association between different ocular dominance and fixation preferences in adolescents with intermittent exotropia (IXT). Methods: In this case serial study, a total of 43 patients with IXT from Aier Institute of Optometry and Vision Science from July to December 2018 participated. With full refractive error correction, the hole-in-the-card test was used to identify sighting dominance, the near point of convergence test was used to determine motor dominance, and a continuous flash technique based on a Gabor patch was used to determine ocular sensory dominance. The preferred eye for fixation was determined by Mayo's office control scale when observing a target at long distance. The degree of agreement between the dominant eye and the preferred eye for fixation was quantified with Kappa statistics. And the association between the above-mentioned concordance and ocular dominance index (ODI) was analyzed by logistic regression. Results: For a total of 43 patients with IXT, sighting dominance, motor dominance, and sensory dominance showed moderate agreement with fixation preference (the Kappa values were 0.46, 0.43, and 0.68, respectively, P<0.001). When there was a clear sensory dominance, the agreement between the sensory dominant eye and the preferred fixation eye was fairly high (Kappa values was 0.86, P<0.001), while the agreements of the other two kinds of ocular dominance and fixation preference were still moderate (the Kappa values were 0.57 and 0.44, respectively, P<0.01). Logistic regression showed that the probability for the preferred fixation eye to agree with the sensory dominant eye increased with the value of ODI (B=0.53, OR=1.70, P<0.001), the greater the ODI value, the higher the probability for agreement between the sensory dominant eye and the preferred fixation eye. Conclusion: For IXT adolescents, there is a consistent relationship between ocular dominance and fixation preference. The results of sensory ocular dominance are more closely related to the preferred eye for fixation, especially when there is a clear sensory dominance, which is more reliable than a sighting dominance test or motor dominance test. Key words: intermittent exotropia; ocular dominance; fixation preference; adolescents

Introduction and PurposeAnisometropia, a relative difference in the refractive state of the two eyes, is common in hyperopic patients. We investigated the association between ocular dominance (sighting dominance) and refractive asymmetry in patients with hyperopia.MethodsThis retrospective study included 223 hyperopic patients with a mean age of 10.1 ± 3.6 years (range 3 to 21 years). Refractive error was measured with cycloplegic refraction, and axial length was measured with IOLMaster® (Carl Zeiss Meditec, Dublin, CA). Ocular dominance was assessed with the hole-in-the-card test. The amount of hyperopic anisometropia was subdivided into four groups: less than 0.50 D, 0.50–0.99 D, 1.00–1.99 D, and 2.00 D or greater.ResultsOcular dominance of the right and left eye was seen in 66% and 34% of the patients, respectively. The nondominant eye had higher hyperopia, astigmatism, and shorter axial length than the dominant eye (P < 0.001). In the group with spherical equivalent anisometropia of ≥0.50 D in particular, the nondominant eye was significantly more hyperopic and had shorter axial length than the dominant eye (both P < 0.001).ConclusionsThe current study revealed that the nondominant eye had a greater hyperopic refractive error and shorter axial length than the dominant eye, in patients who had a high degree of anisometropia in particular.

조경진 1 ⋅김소열 2 ⋅양석우 1 가톨릭대학교 의과대학 안과 및 시과학교실 1 , 평화의 빛 성모안과 2 목적: 우세안의 결정에 관여하는 요소 중 굴절이상에 대하여 분석하여 우세안과 비우세안과의 차이를 알아보고자 하였다.대상과 방법: 근시성 난시 환자 62명을 대상으로 양안 시력교정 후, hole-in-the-card test의 방법을 사용하여 우세안을 결정한 후, 나안시력, 굴절검사, 안압 등을 측정하였다

To investigate the differences between dominant and nondominant eyes in a predominantly young patient population by analyzing the angle kappa, pupil size, and center position in dominant and nondominant eyes. A total of 126 young college students (252 eyes) with myopia who underwent femtosecond laser-combined LASIK were randomly selected. Ocular dominance was determined using the hole-in-card test. The WaveLight Allegro Topolyzer (WaveLight Laser Technologies AG, Erlangen, Germany) was used to measure the pupil size and center position. The offset between the pupil center and the coaxially sighted corneal light reflex (P-Dist) of the patients was recorded by the x- and y-axis eyeball tracking adjustment program of the WaveLight Eagle Vision EX500 excimer laser system (Wavelight GmbH). The patient's vision (uncorrected distance visual acuity [UDVA], best-corrected visual acuity (BCVA), and refractive power (spherical equivalent, SE) were observed preoperatively, 1 week, 4 weeks, and 12 weeks postoperatively, and a quality of vision (QoV) questionnaire was completed. Ocular dominance occurred predominantly in the right eye [right vs. left: (178) 70.63% vs. (74) 29.37%; p < 0.001]. The P-Dist was 0.202 ± 0.095 mm in the dominant eye and 0.215 ± 0.103 mm in the nondominant eye (p = 0.021). The horizontal pupil shift was - 0.07 ± 0.14 mm in dominant eyes and 0.01 ± 0.13 mm in nondominant eyes (p = 0.001) (the temporal displacement of the dominant eye under mesopic conditions). The SE was negatively correlated with the P-Dist (r = - 0.223, p = 0.012 for the dominant eye and r = - 0.199, p = 0.025 for the nondominant eye). At 12weeks postoperatively, the safety index (postoperative BDVA/preoperative BDVA) of the dominant and nondominant eyes was 1.20 (1.00, 1.22) and 1.20 (1.00, 1.20), respectively, and the efficacy index (postoperative UDVA/preoperative BDVA) was 1.00 (1.00, 1.20) and 1.00 (1.00, 1.20), respectively; the proportion of residual SE within ± 0.50 D was 98 and 100%, respectively. This study found that ocular dominance occurred predominantly in the right eye. The pupil size change was larger in the dominant eye. The angle kappa of the dominant eye was smaller than that of the nondominant eye and the pupil center of the dominant eye was slightly shifted to the temporal side under mesopic conditions. The correction of myopia in the dominant and nondominant eyes exhibits good safety, efficacy, and predictability in the short term after surgery, and has good subjective visual quality performance after correction. We suggest adjusting the angle kappa percentage in the dominant eye to be lower than that of the nondominant eye in individualized corneal refractive surgery in order to find the ablation center closest to the visual axis.

To determine the nature of hyperopia in children with accommodative refractive esotropia (ARE) by evaluating the relationships between corneal radius (CR), axial length (AL), age and equivalent spherical refraction (SEQ). A total of 112 children with ARE were included in the study. The children underwent an overall ophthalmic examination including cycloplegic refraction, keratometry and ultrasonic AL measurement. Statistical analysis revealed a strong relationship between AL and SEQ (p < 0.001). A significant correlation was also found between AL and CR (p < 0.001). The relationship between AL and age was weak but statistically significant (p = 0.02). Multiple regression analysis, using SEQ as the dependent variable and CR, AL and age as independent variables, revealed that AL accounts for 43.5% of the variance, and the combination of CR and AL accounts for 60.9% of the variance. Hyperopia is predominantly axial in nature in children with ARE. However, other refractive components are also involved in producing hyperopic refractive errors.

To investigate the relation between sighting and sensory eye dominance and attempt to quantitatively examine eye dominance using a balance technique based on binocular rivalry. The durations of exclusive visibility of the dominant and nondominant eye target in binocular rivalry were measured in 14 subjects. The dominant eye was determined by using the hole-in-card test (sighting dominance). In study 1, contrast of the target in one eye was fixed at 100% and contrast of the target in the other eye was varied from 100% to 80% to 60% to 40% to 20%, when using rectangular gratings of 1, 2, and 4 cycles per degree (cpd) at 2 degrees, 4 degrees , and 8 degrees in size. In study 2, contrast of the target in the nondominant eye was fixed at 100% and contrast of the target in the dominant eye was varied from 100% to 80% to 60% to 40% to 20%, when using a rectangular grating of 2 cpd at 4 degrees in size. In study 1, the total duration of exclusive visibilities of the dominant eye target; that is, the target seen by the eye that had sighting dominance was longer compared with that of the nondominant eye target. When using rectangular gratings of 4 cpd, mean total duration of exclusive visibility of the dominant eye target was statistically longer than that of the nondominant eye target (p < 0.05). In study 2, reversals (in which duration of exclusive visibility of the nondominant eye becomes longer than the dominant eye when the contrast of the dominant eye target is decreased) were observed for all contrasts except for 100%. The dominant sighting eye identified by the hole-in-card test coincided with the dominant eye as determined by binocular rivalry. The contrast at which reversal occurs indicates the balance point of dominance and seems to be a useful quantitative indicator of eye dominance to clinical applications.

To study the change of the dominant eye in the age-related cataract patients before and after surgery, to analyze the correlation between the orientation of the dominant eye and the visual quality, and to observe whether the patients with the change in dominant eye were converted to dizziness. Methods: A total of 44 patients, with age-related cataract between 60 and 80 years old were enrolled. Group A: the non-dominant (secondary) eye served as the surgical eye (n=35); Group B: the dominant eye served as the surgical eye (n=9); Group C: the operation was performed on the contralateral eye after a month (n=28). Measurement of the dominant eye was performed before operation, 1 week after operation and 1 month after the operation. The changes in the uncorrected distance visual acuity (UCDVA), contrast sensitivity (CS), best corrected visual acuity (BCVA) and spherical equivalent (SE) between the dominant and non-dominant eye were compared. Results: The UCDVA, CS, BCVA and SE were significantly improved at 1 day after the operation. There was significant difference between the 2 groups (P<0.05). Preoperative: in group A, the UCDVA, CS, BCVA of ocular dominance were better than the non-dominant eye with significant difference (P<0.05), while there was no significant difference between the SE (P>0.05); in group B, the UCDVA, CS, BCVA in the dominant eye were better than the non-dominant eye's, but the difference was not statistically significant (P>0.05). After operation: the UCDVA, CS and BCVA in the dominant eye in group A and group B were higher than those of the non-dominant eye with statistical difference (P<0.05), but there was no statistical difference between SE (P>0.05). The dominant eye's transformation occurred in group A when the non-dominant eye's postoperative visual quality improved over the leading eye. The transformation rate was 60% in 1 week, and the conversion rate was 80% in 1 month. In group C, the dominant eye reduction rate was 100%, and the visual quality was not significant difference between the two eyes (P>0.05). After the operation, the patients with the dominant eye's transformation felt discomfort, which could be relieved within 1 week. Conclusion: The location of the dominant eye was correlated with uncorrected visual acuity, contrast sensitivity, and the best corrected visual acuity. The dominant eye's transformation occurred when the non-dominant eye's postoperative visual quality improved over the leading eye after the surgery. If the contralateral eye's surgery was performed in a short term, the dominant eye can be returned to the initial state.

Objective To investigate the distribution of ocular dominance in myopic patients before and after laser in situ keratomileusis (LASIK) surgery, and the effects of the change in ocular dominance. Methods A prospective study was performed on 190 myopic patients (380 eyes) who received LASIK treatment. The dominant eye was identified with the hole-in-the-card test. Before operation, the patients were divided into 3 groups based on anisometropia and ocular dominance.Group A, 154 cases, the spherical equivalent difference was less than 1.75 D between the two eyes;group B, 19 cases, the spherical equivalent difference was 1.75 D or more between the two eyes and the dominance eye with higher diopter; group C 17 cases, the spherical equivalent difference was 1.75 D or more between the two eyes and the dominance eye with lower diopter. Refraction, ocular dominance and visual acuity were evaluated in all patients preoperatively and 1 month postoperatively.As part of the investigation, patients answered questionnaires after the operation. Chi-square test was used to compare the rate of dominance change, independent samples t test was used to compare the difference of measurement data. Results Before LASIK, 125 patients (65.8%) had right-eye dominance and 65 patients (34.2%) had left-eye dominance. After the operation, 92 patients (48.4%)had right-eye dominance and 98 patients (51.6%) had left-eye dominance, with 59 patients (31.1%)changing dominance. In group B, there was a higher rate of change in ocular dominance in eyes with greater anisometropia (47%)compared to groups A (29%) and C (29%) (x2=5.38, P＜0.05).Before operation, the equivalent spherical between dominant eye and the other was without any significant difference. After the operation, the dominant eyes' refractive error was (-0.29±0.89)D,lower than the preoperative dominant eyes (-0.42±0.91)D (t=2.448, P=0.015). The questionnaires did not show any statistically significant differences between dominance change group and no change group. Conclusion This study shows there is a change in ocular dominance after LASIK surgery,especially in those the dominance eye with higher diopter before operation. But the change has few effects on euphoropsia. Therefore, ocular dominance has plasticity after the critical period. The nondominant eyes have a greater degree of myopia than dominant eyes in subjects who had the operation. Key words: Keratonileusis,laser in situ; Dominant eye; Ocular dominance column; Plasticity

It is commonly assumed that one eye is dominant over the other eye. Eye dominance is most frequently determined by using the hole-in-the-card test. However, it is currently unclear whether eye dominance as determined by the hole-in-the-card test (so-called sighting eye dominance) generalizes to tasks involving interocular conflict (engaging sensory eye dominance). We therefore investigated whether sighting eye dominance is linked to sensory eye dominance in several frequently used paradigms that involve interocular conflict. Eye dominance was measured by the hole-in-the-card test, binocular rivalry, and breaking continuous flash suppression (b-CFS). Relationships between differences in eye dominance were assessed using Bayesian statistics. Strikingly, none of the three interocular conflict tasks yielded a difference in perceptual report between eyes when comparing the dominant eye with the nondominant eye as determined by the hole-in-the-card test. From this, we conclude that sighting eye dominance is different from sensory eye dominance. Interestingly, eye dominance of onset rivalry correlated with that of ongoing rivalry but not with that of b-CFS. Hence, we conclude that b-CFS reflects a different form of eye dominance than onset and ongoing rivalry. In sum, eye dominance seems to be a multifaceted phenomenon, which is differently expressed across interocular conflict paradigms. Finally, we highly discourage using tests measuring sighting eye dominance to determine the dominant eye in a subsequent experiment involving interocular conflict. Rather, we recommend that whenever experimental manipulations require a priori knowledge of eye dominance, eye dominance should be determined using pretrials of the same task that will be used in the main experiment.

목적: 양안으로 사물을 주시할 때 우세안을 주로 사용한다. 이러한 이유로 안경과 콘택트렌즈 처방 시 우세안의 중요성이 크다. 이를 위해 본 연구는 연령대별로 구분하여 양안에 있어서 굴절력의 변화에 따른 우세안과 비우세안의 시력 차이가 있는지 알아보았다. 방법: 안질환이 없는 186명을 대상으로 Hole-in-the-card test법을 통한 우세안을 검사하였다. 검사의 일관성을 위해 동일인이 측정하였으며, 검사의 신뢰성을 높이기 위해 3회 반복 실시하였다. Spss통계를 통해 굴절력에 따른 우세안과 비우세안의 상관관계를 알아보았다. 결과: 대상자 186명 중 우안 우세안은 135명, 좌안 우세안은 51명이었다. 굴절이상 환경에 노출되기 시작하는 10세 이전(평균 <TEX>$8.8{\pm}1.18$</TEX>세)과 본격적으로 굴절이상이 발생하는 10세에서 20세 사이(평균 <TEX>$14.1{\pm}2.58$</TEX>세), 그리고 시력안정화 시기에 접근하는 20세 이후(평균 <TEX>$51.8{\pm}17.51$</TEX>) 모두 우세안의 시력이 비우세안보다 시력이 높았지만 통계적으로 유의하지 않았다. 근시성 난시에 있어서 우세안의 난시 굴절력 평균값이 비우세안 난시안의 평균값보다 작게 나타났으며, 통계적으로 유의한 결과를 나타내었다(p=0.017<0.05). 결론: 양안 중에서 전체적으로 난시도가 작고 균형 잡힌 눈이 우세안으로 선택될 확률이 높다고 판단된다. Purpose: When we look at the object, we used the dominant eye mainly. For this reason, a prescription of the dominant eye is an important factor for glasses and contact lenses. This study evaluated visual acuity differences between dominant and nondominant eyes through analyzing refractive power changes in both eyes by the ages. Methods: This study was performed to investigate the relationship between refractive error and dominant eye which had the superiority in the function of binocular. 186 subjects without ocular disease were examined on the dominant eye. The dominant eye was examined by the Hole-in-the-card test. For the consistency of the measurements, we tested refractive power in three times by the same person. Results: Using SPSS, the relationship between vision and the dominant eye was analyzed. 135 people of the whole subjects have the dominant eye on right. The Number of the non-dominant eye is 51. We were divided into 3 types, the group under the age of 10 that begins to expose environment factor affect on vision (the average age <TEX>$8.8{\pm}1.18$</TEX>) and the age group of 10 to 20 that begins to change refractive power in earnest (the average age <TEX>$14.1{\pm}2.58$</TEX>) and the group after the age 20 that began to stabilize vision (the average age <TEX>$51.8{\pm}17.51$</TEX>). The visual acuity of dominant eye was higher than non-dominant eye in all age groups. Nevertheless, these results were not statistically significant. Mean astigmatism of dominant eye was smaller than the non-dominant eye, and this is significant, statistically (p=0.017<0.05). Conclusions: It is expected that the balanced eye with a lower level of astigmatism has a more possibility become a dominant eye.