The symptoms and signs associated with convergence insufficiency are related to prolonged, visually-demanding, near-centered tasks. They may include, but are not limited to, diplopia (double vision), asthenopia (eye strain), transient blurred vision, difficulty sustaining near-visual function, abnormal fatigue, headache, and abnormal postural adaptation, among others. Note that some Internet resources confuse convergence and divergence vergence dysfunction, reversing them.
Many common symptoms of convergence insufficiency are that words appear to move, float, swim or dance around the page. Skipping over words or skimming is also associated with convergence problems as is frequent loss of place, closing one eye when reading, inability to concentrate and feeling sleepy or falling asleep while reading. Some more unusual symptoms of convergence insufficiency are feeling dizzy while reading, or that their head spins or that the words spin around the page. Some of the symptoms of convergence insufficiency are the same as dyslexia. I have found that most patients with dyslexia that I have seen also have convergenge insufficiency. I would say that dyslexia is just the term used when they haven’t had their eyes lined properly.
Depth Perception and 3D
Many patients who are unable to see 3D movies, pictures or slides or who seem them with much difficulty may also have convergence insufficiency. Depth perception and 3D is not fun for people with convergence insufficency, it is just a headache.