Effectiveness of a structured three-week vergence training program in reducing symptoms of convergence insufficiency: a prospective interventional study

   Background. Convergence insufficiency is a common binocular vision disorder characterized by eyestrain, headaches, and blurred vision during near tasks. Vision therapy interventions involving vergence and oculomotor training aim to improve binocular coordination and reduce associated symptoms. Evidence suggests that short-term structured vision therapy programs may improve vergence function and visual comfort, highlighting the clinical importance of effective therapeutic approaches for individuals with high near-work demands.

   Purpose: to evaluate the effectiveness of a short-term targeted vision therapy program in improving the near point of convergence (NPC) and reducing symptoms of convergence insufficiency in young adults.

   Materials and methods. Thirty participants aged 18–25 years were enrolled and divided into two groups: an intervention group (n = 15) that received vision therapy and a control group (n = 15) that received no intervention. NPC was measured before and after the intervention using a Royal Air Force (RAF) rule. Objective refraction was determined by retinoscopy, and subjective refraction was also assessed. Symptom severity was evaluated using the Convergence Insufficiency Symptom Survey (CISS). The intervention group completed a three-week vision therapy program comprising vergence and oculomotor exercises. Non-therapeutic relaxation activities were used only as preparatory tasks.

   Results. Following the three-week intervention, mean NPC decreased from 8.4 ± 1.1 cm to 7.6 ± 1.0 cm in the intervention group, whereas only a minimal change was observed in the control group (from 8.3 ± 1.2 cm to 8.2 ± 1.1 cm). CISS scores decreased significantly from 33.0 ± 3.8 to 14.0 ± 2.9 in the intervention group, compared with a slight decrease from 32.0 ± 4.1 to 30.5 ± 3.6 in the control group. No significant changes in cylinder power or axis were observed in either group.

   Conclusion. The structured vision therapy program improved NPC and reduced symptoms associated with convergence insufficiency in young adults. These findings suggest that short-term interventions may improve binocular function, particularly in individuals who experience symptoms during sustained near work.

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