What is convergence insufficiency

What is convergence insufficiency?

Convergence insufficiency is the inability or lack of ability to keep the eyes straight when reading or doing close work.

The eyes tend to drift outwards causing double vision. Trying to control the double vision can lead to headaches, blurred vision, difficulty concentrating, movement of print when reading and symptoms of sore eyes. These symptoms often become worse when tired or unwell. If left untreated children often resort to avoiding close work.

Causes of convergence insufficiency

Convergence insufficiency is due to weakness in the muscles which bring the eyes in towards the nose together or can be secondary to other causes.

How do exercises work?

The exercises work by using targets to train the weak eye muscles. Different exercises are available depending on the symptoms and the progress made.

How often do I need to do the exercises?

This will be decided by your orthoptist and will be explained verbally and written information is provided. The amount will vary depending on the symptoms.

To begin with, the exercises will might to cause eye strain or headaches. If you feel like this is happening, you can stop and return to the exercises at a later time. You must rest your eyes after doing the exercises either by looking in the distance or closing your eyes for a few minutes.

How long will treatment last?

If the exercises are performed correctly in the routine given by your orthoptist, treatment should last no longer than 12 weeks. This can vary depending on the severity of the convergence insufficiency.

How do we do the exercises?

Your orthoptist will explain and demonstrate the exercises to you. There are instructions available as part of this information.

Smooth convergence

A small, detailed target will be recommended by your orthoptist.

You need to hold this target, such as a letter on a stick, at arms length and slowly brought towards your nose. If you see the letter split into 2 letters, then stop moving the letter and try to make it single. If you cannot make it single, move the letter target back out until it becomes single and re-try.

The key is to do this slowly and not to rush.

If you are not able to bring it any closer after trying for 5 minutes, then have a break and try again at a later time.

Your orthoptist will recommend how many times you need to do the exercises in the day. Try and be consistent with this as much as you can.

1. Hold a target (such as a pen) at arm’s length, at a slightly lower position.
2. Focus your eyes on the pen and smoothly bring it towards your nose, at a steady speed.
3. When the pen appears double, hold it still. Aim to get it as close as possible to your nose without it appearing double
4. Try to turn your eyes in together until the pen becomes single again, this will often take a lot of effort. If you are not able to turn your eyes together to make a single image, move the pen back smoothly and slowly until it becomes single. Then practise working from this point and continue with the next step.
5. Count how long the pen appears single at this point. This will give you an idea of how well you can maintain a single image.

After doing the exercise it is important that you relax your eyes by looking into the distance or by closing them for a minute or so. When you start the exercise you may feel increased eye strain and get headaches. This is normal, and will improve the more you do the exercise.

Dot card

Hold the card at the end of your nose and focus on the furthest away dot making it single. Once the furthest away dot is single look to the next dot and make this single, each time moving closer to your face once the previous dot is single. If you cannot make a dot single, move to the dot above and re-try.

Example of dot card

Incorrect Correct

Jump convergence

Hold a single target, for example a letter at arms length.

Pick a different target in the distance for example a clock and make this single.

Focus on the letter making sure it is single then focus on clock again keeping it single. Continue to look from one target to the other while moving the letter closer to your nose each time you re-focus on this.

Prescription

You should do:

The exercise must be done times in the day for minutes.

Once you have done your prescribed exercise, it is important to rest your eyes by looking far away into the distance or your eyes for minutes.

Remember to take it slow.

Keep doing the exercises till your next appointment even if you feel like the symptoms are getting better