Aug 2026· Annals of Medicine & Surgery· 0 citations· 25 references
TL;DR
It is suggested that when low myopic astigmatism is corrected using spherical-equivalent soft contact lenses, certain binocular vision parameters may demonstrate acute changes and careful binocular vision assessment may therefore be beneficial when prescribing simplified spherical correction in astigmatic patients.
Abstract
To investigate the acute, same-day changes in binocular vision parameters when switching from spectacle wear to spherical-equivalent soft contact lens wear in patients with low myopic astigmatism.
This acute, same-day comparative study included 36 participants aged 15–35 years with low myopic astigmatism. A comprehensive binocular vision assessment – including accommodative amplitude (AA), accommodative facility (AF), stereoacuity, cover test, horizontal phoria, near point of convergence (NPC), negative relative accommodation (NRA), positive relative accommodation (PRA), positive fusional vergence, negative fusional vergence, and lag of accommodation – was performed with both spectacles and spherical-equivalent soft contact lenses. Measurements were obtained following a 30-minute lens stabilization period. Mean differences between conditions were analyzed using paired
t
-tests that accounted for within-subject correlation.
When comparing spherical-equivalent soft contact lenses with spectacles, small but statistically significant differences were observed in selected binocular parameters. The NPC was slightly more receded with contact lenses, with a mean difference of −0.36 ± 0.76 cm compared with spectacles (
P
< 0.01). The lag of accommodation showed a small reduction with contact lens wear (mean difference: −0.11 ± 0.31 D;
P
= 0.03). PRA was modestly increased with contact lenses, with a mean difference of +0.35 ± 0.16 D (
P
= 0.03). No statistically significant differences were found between spectacles and contact lenses for AA, AF, stereoacuity, cover test findings, horizontal phoria, NRA, positive fusional vergence, or negative fusional vergence (all
P
> 0.05).
These findings suggest that when low myopic astigmatism is corrected using spherical-equivalent soft contact lenses, certain binocular vision parameters may demonstrate acute changes. Careful binocular vision assessment may therefore be beneficial when prescribing simplified spherical correction in astigmatic patients.
OBJECTIVE
This study compared the binocular and accommodative efficiency of young adults with myopic isometropia versus myopic anisometropia, difference spherical equivalent refraction (SER) ≥ 1.00 diopter (D), when corrected with ophthalmic versus contact lenses.
METHODS
Seventy-two participants were categorized into isometropic (n = 36; age 21.92 ± 3.21 years) and anisometropic (n = 36; age 21.44 ± 2.62 years) myopia groups. Binocular and accommodative parameters were clinically evaluated under both ophthalmic and contact lens correction.
RESULTS
Ophthalmic lens correction produced no significant differences (p > 0.05) in binocular visual efficiency between the two groups. Conversely, contact lens correction elicited distinct alterations in accommodative and vergence profiles. Myopic anisometropia showed a highly significant increase in accommodative lag when using contact lenses (p < 0.001) and increased negative relative accommodation (p = 0.007) compared to ophthalmic lenses. Furthermore, contact lenses amplified the fusional divergence demand to compensate for esophoria, thereby diminishing the near negative fusional vergence reserve (p = 0.012). Notably, contact lens wear was associated with better stereoacuity compared to ophthalmic lenses, which suggests a potential functional advantage in stereopsis for higher degrees of anisometropia, though this warrants further exploratory validation.
CONCLUSION
In conclusion, while contact lenses distinctly alter accommodative and vergence dynamics, they may offer functional advantages in stereopsis for higher degrees of anisometropia. These comparative insights provide valuable clinical guidance for selecting refractive correction modalities to support specific binocular functions and stereoscopic performance.
Adithep Daradas, Busita Sankapong, Chanida Klamsakun et al.· Journal of Optometry· 0 citations
Purpose To evaluate multi-distance binocular visual function in children using a tablet-based dichoptic platform and compare performance between single-vision and highly aspherical lenslet (HAL) spectacle lenses. Methods This cross-sectional study included 300 children aged 4 to 17 years wearing single-vision spectacle lenses (n = 154) or HAL spectacle lenses (n = 146). Outcomes included foveal simultaneous-perception non-composite responses, peripheral simultaneous-perception non-normal responses, and fine, dynamic, and gross stereopsis from 0.4 to 3.0 m. Generalized estimating equations clustered by participant evaluated lens type and testing distance, with adjustment for age, sex, myopia magnitude, interocular spherical-equivalent difference, and mean absolute cylinder. Results Fine stereopsis declined significantly as testing distance increased and was rarely measurable at 2.0 m. Compared with 0.4 m, the adjusted odds of measurable fine stereopsis were lower at 1.5 m (adjusted odds ratio [aOR] = 0.81; P = 0.003) and 2.0 m (aOR = 0.08; P < 0.001). In adjusted observational analyses, HAL lens wear was associated with higher odds of measurable dynamic (aOR = 1.68; P = 0.024) and gross stereopsis (aOR = 2.51; P = 0.006) than single-vision lens wear. Fine stereopsis remained comparable between the two groups (aOR = 0.99; P = 0.960). Foveal non-composite responses were uncommon at 0.4 m but highly prevalent at 3.0 m (>87%) regardless of lens type, while peripheral simultaneous perception remained mostly normal. Conclusions Tablet-based binocular visual performance declined as the testing distance increased. In this cross-sectional observational analysis, children wearing HAL spectacle lenses showed higher adjusted odds of measurable dynamic and gross stereopsis than those wearing single-vision lenses, while fine stereopsis remained comparable. These findings provide preliminary clinical evidence regarding binocular visual performance with HAL lens wear and warrant confirmation in longitudinal studies across different myopia levels.
Zhuotong Wu, Yuhao Ye, Yong Ma et al.· Clinical Ophthalmology· 0 citations
PURPOSE
To evaluate the impact of toric versus spherical equivalent contact lenses on visual acuity and eye-movement-based reading performance in young adults with low-to-moderate astigmatism, using Chinese reading passages to reflect real-world tasks.
METHODS
A participant-masked, randomised, two-period crossover study was conducted in 28 young adults (aged 18-35 years) with low-to-moderate refractive astigmatism (-0.75 to -2.00 dioptre cylinder [DC]). Participants wore toric and spherical equivalent daily disposable soft contact lenses (SCLs) for 1 week each, in random order. Binocular distance, intermediate and near visual acuity were measured and reading performance was assessed during silent reading of standardised Chinese passages using the EyeLink 1000 Plus. Key metrics included reading speed, fixation count, fixation per minute (fpm), fixation per word (fpw), saccade characteristics and regressions.
RESULTS
Toric lenses significantly improved binocular intermediate visual acuity at 66 cm (-0.11 ± 0.07 vs. -0.07 ± 0.08 logMAR, p = 0.04) and reading speed (345.37 ± 122.41 vs. 322.49 ± 130.65 characters per minute [cpm], p = 0.03), compared with spherical equivalent lenses. Additionally, toric correction was associated with more efficient eye-movement behaviour, including fewer fixations per word, fewer total fixations, fewer total saccades and fewer regressions (all p < 0.05).
CONCLUSION
Toric SCLs improved intermediate visual acuity and Chinese reading performance relative to spherical equivalent correction in young adults with low-to-moderate astigmatism. These findings support the functional benefit of full astigmatic correction for visually demanding mid-range reading tasks.
PURPOSE
To characterize the severity-dependent pattern of accommodative and binocular visual alterations in spectacle-corrected children with myopic anisometropia, normal best-corrected visual acuity (BCVA), and no clinically significant binocular vision-related symptoms.
METHODS
This hospital-based cross-sectional study included 153 myopic anisometropic and 104 myopic isometropic children. Cycloplegic refraction, axial length, ocular dominance, accommodative function, fusional vergence, heterophoria, Worth Four-Dot Test responses, and stereoacuity were assessed. All binocular vision examinations were performed under full spectacle correction. Anisometropia severity was quantified using vector dioptric distance (VDD). Multivariable regression models were used to evaluate associations between VDD and selected accommodative and binocular visual outcomes.
RESULTS
With increasing anisometropia severity, amplitude of accommodation in the nondominant eye decreased from 10.73 ± 3.10 D in the mild group to 9.05 ± 3.12 D in the high group (p-trend = 0.007), and accommodative facility decreased from 8.3 ± 4.4 to 5.5 ± 4.4 cpm (p-trend = 0.005). Interocular accommodative imbalance increased progressively. The prevalence of clinically meaningful near esophoria increased from 5.9% to 33.3% (p-trend = 0.009) and reduced near base-in vergence increased from 10.2% to 42.9% (p-trend = 0.001). Near Worth Four-Dot diplopia increased from 13.7% to 28.0% (p-trend = 0.05). Near stereoacuity worsened progressively across severity strata (p-trend < 0.001). After adjustment for age, binocular mean spherical equivalent, and relevant binocular covariates, increasing VDD remained independently associated with greater interocular accommodative imbalance, reduced near base-in vergence, a higher likelihood of diplopia on the near Worth Four-Dot Test, a more esophoric near phoria value, and poorer near stereoacuity.
CONCLUSIONS
Increasing myopic anisometropia was associated with a severity-dependent pattern of subclinical alterations in accommodative balance, ocular alignment, fusional vergence, sensory fusion, and stereoacuity in spectacle-corrected children with normal BCVA. These findings support a multifactorial interpretation involving accommodative, optical, vergence, and sensory factors; however, their relative contributions and causal sequence cannot be determined from this cross-sectional study. Longitudinal and interventional studies are needed to clarify the mechanisms and clinical significance of these alterations.
Ningxin Dou, Xiaodan Dong, Jiayan Li et al.· Optometry and Vision Science· 0 citations
Purpose: To measure high contrast visual acuity (HCVA) when presbyopic soft contact lens (CL) wearers, requiring a spectacle addition from +0.75 to +1.75 dioptres were fit bilaterally with delefilcon A daily disposable multifocal (DT1 MF) CLs and senofilcon A daily disposable multifocal (AOM MF) CLs. Methods: In this prospective, randomized, double-masked, cross-over, non-inferiority study, presbyopic CL wearers wore two types of multifocal CLs for 1 hour each. HCVA was measured monocularly and binocularly at 6m, 66cm and 40cm under photopic and mesopic conditions. Participants rated subjective visual clarity (0–100 scale, 100=very clear) after each HCVA assessment. Pupil size was assessed under photopic and mesopic conditions. Results: Twenty-eight participants (48.6 ± 5.3 years) completed the study. DT1 MF was non-inferior to AOM MF in HCVA at 6m, 66cm and 40cm in photopic and mesopic conditions for the dominant and non-dominant eye, and binocularly. There were no statistically significant differences between lenses for subjective visual clarity ratings for any of the viewing distances, whether evaluated for photopic or mesopic conditions for the dominant or non-dominant eye or binocularly. Mean pupil size in the dominant eye was 3.6 ± 0.5mm (2.6 to 4.5mm) and 5.1 ± 0.8mm (2.8 to 6.1mm) in photopic and mesopic conditions respectively. HCVA under photopic or mesopic illumination at 6m, 66cm or 40cm was not associated with pupil size (Pearson correlation, all p>0.05). Conclusion: Both lenses provided good vision across a variety of distances at high and low illumination. DT1 MF was non-inferior to AOM MF in HCVA under photopic and mesopic illumination at distance, intermediate and near. HCVA at all distances with both study lenses was independent of pupil size. Despite their different design, both study lenses performed equally well and provide a suitable vision correction for presbyopic CL wearers, irrespective of pupil size.
Ulrike Stahl, Jill Woods, Alison Ng et al.· Clinical Ophthalmology· 0 citations
AIM
To evaluate changes in visual acuity and accommodation function following femtosecond laser-assisted in situ keratomileusis (FS-LASIK) combined with monovision in patients aged over 40y.
METHODS
This prospective, non-randomized cohort study included patients who were divided into an FS-LASIK binocular group (full correction) and an FS-LASIK monovision group. The binocular group consisted of Group 1 (15 patients) with simple myopia and Group 2 (12 patients) with myopia and presbyopia. The monovision group (Group 3) included 13 patients with myopia and presbyopia. Parameters assessed included the uncorrected distance visual acuity (UCVA), the uncorrected near visual acuity (UNVA), contrast sensitivity (CS), binocular cross-cylinder (BCC), accommodative amplitude (AMP), positive relative accommodation (PRA), negative relative accommodation (NRA), and accommodative facility (AF). Patient satisfaction was evaluated at 3mo postoperatively.
RESULTS
A total of 40 patients (80 eyes) were enrolled (mean age 43.63±3.666y; 12 males). At 3mo after FS-LASIK, UCVA improved significantly in all patients (P<0.001), while UNVA remained comparable to preoperative levels (P>0.05). BCC in Group 3 decreased by 0.30±0.43 compared to preoperative levels, showing a statistically significant difference (P=0.037). The AMP in Group 3 showed an increasing trend with greater improvement in the nondominant eye than in the dominant eye (P>0.05). Patient satisfaction was high in all groups.
CONCLUSION
FS-LASIK combined with monovision is an effective treatment for patients aged over 40y with myopia and presbyopia, which not only improves visual acuity but also achieves high patient satisfaction and improves postoperative BCC.
Yuanyuan Qi, Qi Li, Gui-Li Wang et al.· International Journal of Oph...· 0 citations