The exact cause of convergence insufficiency is not always clear, but it is believed to involve a disruption in the normal coordination of eye movements. Factors that may contribute to CI include:

1. Eye Muscle Weakness: Weakness or imbalance in the eye muscles responsible for convergence.
2. Poor Posture: People not maintaining proper posture while using mobiles or reading tend to have higher chances to develop convergence insufficiency.
3. General Body Weakness: Vitamin deficiencies, minerals deficiencies or iron deficiencies are also some of the common risk factors.   
4. Genetic Factors: There may be a genetic component, as convergence insufficiency can run in families.
5. Eye Disorders: Certain eye conditions or disorders may contribute to convergence insufficiency.

1. Eye Strain: Individuals with convergence insufficiency may experience eye strain, especially during or after reading or other close-up activities.
2. Double Vision: Double vision, also known as diplopia, can occur when the eyes fail to converge properly.
3. Headaches: Persistent headaches, often located around the eyes or forehead, may be a symptom of convergence insufficiency.
4. Difficulty Reading: Reading may become challenging, and individuals may report words appearing blurry or moving on the page.
5. Watery Eyes: Watery eyes specially while using mobile phones & other near vision tasks.

Convergence insufficiency is diagnosed through a comprehensive eye examination. This may involve a series of tests to assess eye movements, focusing abilities, and the ability of the eyes to work together commonly called as Binocular Vision Evaluation done by an Optometrists who has specialized into Vision Therapy.

The therapy plan is tailored to the individual needs of the patient, taking into account their age, visual demands, and overall health.

Vision therapy often involves a series of eye exercises and activities that are designed to improve the coordination of the eye muscles.

These exercises may include activities that require the eyes to converge (come together) and diverge (move apart) efficiently, helping to enhance the flexibility and control of the eye muscles. 

These exercises may involve the use of various tools and techniques, such as:

Pencil Push-ups: Most common but most ineffective therapy to treat CI. Patients focus on a small letter or object on a pencil and slowly bring it closer to their nose until they experience double vision. The goal is to improve convergence abilities.

Brock String Exercises: This involves using a string with coloured beads at various intervals. The individual focuses on the beads, and as they converge or diverge their eyes, they work on improving eye coordination.

Computer-Based Activities: Some vision therapy programs use specialized computer programs and exercises to enhance eye coordination and convergence skills.

Prism Glasses: These glasses may be prescribed to help alleviate symptoms of convergence insufficiency by altering the way light enters the eyes and promoting better alignment.

Home Exercises: Patients may be given specific exercises to practice at home to reinforce the progress made during in-office vision therapy sessions.

Integration into Daily Activities:

The ultimate goal of vision therapy is to improve the efficiency of the visual system in real-life situations, such as reading, using a computer, or other near-vision tasks.