The effectiveness of dichoptic therapy in treating convergence insufficiency: a pilot randomized control trial

Background: Convergence insufficiency (CI) is a common non-strabismic binocular vision disorder that causes eyestrain, headaches, diplopia and difficulty concentrating during near tasks. It is especially prevalent among young adults who perform prolonged near work, such as university students. Vision therapy remains the mainstay for CI management. While traditional office-based and home-based therapies are effective, newer technology-driven methods such as dichoptic mobile therapy have recently emerged. However, evidence supporting their efficacy remains limited. Aim: To evaluate the effectiveness of dichoptic mobile therapy in improving binocular vision parameters in individuals with convergence insufficiency compared to a placebo control. Methodology: Fourteen volunteers aged 18–25 years with symptomatic CI were recruited and randomly assigned to an experimental group (using red–green anaglyph filters) or a placebo group (without filters). Both groups completed 20 minutes of therapy. Pre- and post-therapy assessments included visual acuity, near point of convergence (NPC), negative and positive fusional vergence (NFV, PFV), amplitude of accommodation (AA), accommodative facility and vergence facility. Data were analysed using SPSS version 20. Result: The experimental group demonstrated significant improvement in near PFV and vergence facility following therapy. No significant changes were observed in NPC, NFV, AA or accommodative facility. Between-group differences were not statistically significant. Conclusion: Dichoptic mobile therapy using red–green filters shows a potential for improving near PFV and vergence facility in individuals with convergence insufficiency. Further studies with larger sample sizes and extended intervention periods are recommended to validate these findings.