Bifocal Soft Lenses Effective in Adolescents with Myopia and Small-angle IXT, Study Finds

Compared to single-vision or ortho-K contact lenses, defocus soft lenses with a concentric bifocal design were found to be more effective in enhancing eye position control and overall visual function in the study population, consisting of patients aged eight to 18 with myopia and small-angle IXT who previously underwent surgery for IXT. Photo: Mohamed F. Farid. Click image to enlarge. Up to 20% of patients with intermittent exotropia (IXT), a common form of strabismus, may require secondary surgical interventions due to undercorrection from the initial surgery and underlying accommodative and visual function issues. Concurrent myopia exacerbates these issues, creating a cycle where myopia progression leads to IXT recurrence. While orthokeratology (ortho-K) and single-focus soft contact lenses are used to manage myopia in IXT patients, gaps remain in understanding their impact on IXT eye position stability. A recent study compared the clinical effects of three contact lens types—bifocal soft lenses, single-focus soft lenses and ortho-K lenses—in patients with IXT accompanied by myopia, finding that the former lens type was most effective in enhancing eye position control and overall visual function after IXT surgery.The randomized controlled trial included a total of 142 children and adolescents, aged eight to 18 years, all of whom had small-angle IXT, previously underwent IXT surgery and presented with concurrent myopia. Participants were randomly assigned into three groups: one group received bifocal soft contact lenses, the second was fitted with single-focus soft contact lenses and the third used ortho-K lenses. Over the course of one year, multiple visual function parameters were assessed, including best-corrected visual acuity (BCVA), contrast sensitivity, accommodative function and the ability to control eye position. The objective was to identify any significant changes in strabismus degree, axial length growth and the overall ability to maintain proper binocular coordination.No significant differences in BCVA were found among the three groups, suggesting that the basic visual acuity correction effects were comparable between each contact lens type. However, the results did indicate that bifocal soft contact lenses notably enhanced eye position control and led to significant improvements in visual function compared to the other two methods. Specifically, patients in the bifocal lens group demonstrated a marked reduction in strabismus angle and showed the greatest improvements in positive fusional convergence and contrast sensitivity. The data showed that the strabismus angle showed a positive correlation with near stereopsis acuity and eye position control scores, while exhibiting a negative correlation with near horizontal positive fusional convergence.Although the single-focus lenses provided some benefits in terms of comfort and visual acuity correction, they did not yield the same level of efficacy as bifocal lenses in enhancing eye position control and overall visual function. As for the ortho-K group, this intervention proved beneficial for myopia control but showed limited effects on eye position stability. “After the initial IXT surgery, patients wearing defocus soft contact lenses with a concentric bifocal design can effectively control axial length growth, enhance eye position control ability, improve visual function and achieve good subjective visual outcomes,” the researchers summarized in their paper. Therefore, they surmised that bifocal soft contact lenses along with visual training could help avoid a second surgery for IXT in adolescents with myopia, small-angle IXT and a history of first-time surgery for intermittent exotropia, especially in youth with convergence insufficiency-type IXT. Click here for the journal source. Yu J, Zhou YH. Clinical analysis of the effects of different types of contact lenses on the correction of myopia with small-angle strabismus and visual function. Eye Contact Lens. October 31, 2025. [Epub ahead of print] . This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.