Your eyes converge when you focus on near objects like reading a book, tying your shoe or sending a text message. Convergence insufficiency limits a person's ability to work with visual information at close distances. Convergence insufficiency can even limit entertainment or leisure activities. According to an article in the Khaleej Times, convergence insufficiency may prevent people from seeing three-dimensional movies, because 3D glasses require healthy convergence and strong vision.
Get a pencil and hold it directly in front of your face with your arm fully extended. Look directly at the pencil. Focus on the pencil as you slowly move it toward your nose along an imaginary line. Bring the pencil as close to your nose as possible until you can no longer maintain a single image of the pencil and you shift to a double image of the pencil. Practice this exercise three to four times a day and build on your ability to bring the pencil closer and closer to your nose while maintaining a single image of the pencil.
Get two different color pencils and stand about five feet in front of a solid-colored wall. Face the wall directly and hold one pencil in one hand with your arm fully extended in front of your face. Hold the other pencil with the other hand with your arm extended midway between your nose and the other pencil. Line up the pencils so that if you connected them with a string, the string would be at a 90-degree angle to your face. Look at the pencil that is further away. While looking at the further pencil, you should see the closer one in double. Look at the closer pencil. You should see the further pencil in double by looking at the closer pencil. Shorten the distance between your nose and both pencils and look at each of them again. Repeat this exercise until you are unable to avoid double vision when looking directly at one of the pencils.
Draw a straight line in the middle and across the length of a sheet of paper or cardboard. Draw five or more dots equally spaced along the line with different color inks or alternating colors. Let the ink dry for a few minutes and raise the sheet of paper up to your nose. Position the paper so that the line extends outward in front of your face and you can see the dots on the line. Look at the furthest dot for 10 seconds. The rest of the dots should form a blurry shape that looks similar to the letter A. Move to the next closest dot if you can maintain a single image of the furthest dot. Continue moving closer, looking at each dot for several seconds until you can no longer maintain a single image of the dot that you look at directly. The blurry A shape should gradually transform into a blurry V-like shape as you focus on points that are closer to your nose.