During an examination, blurry vision is usually the biggest complaint a patient has. Patients do not realize that they are seeing two images at the same time since there is often an overlap between the two images, so they report blurry vision. Or they may not even talk about their symptoms as a symptom of vision, but rather how it impacts their function. So instead of saying they have diplopia (double vision) or even blurry vision, they may say that they are experiencing difficulty focusing when they read.
When we do a neuro optometric eye exam we are discussing with the patient their visual function. Most people will not know how to explain the symptom divorced from function. For example, students who have suffered a concussion may not realize that they have suffered a concussive injury that can lead to post-traumatic vision syndrome. They will complain that they can't concentrate, that their brain feels foggy. They may share that their reading comprehension has fallen dramatically since they had a concussion. They may explain that it is impossible for them to read for long periods of time, forcing them to give up on what they are reading after a short while.
Convergence insufficiency affects the ability of your eyes to work together when looking at nearby objects. This may result in blurry or double vision when you see things up close, like a book or smartphone screen.
There is a difference between convergence insufficiency and exotropia, which is a subtype of strabismus (eye misalignment). Individuals with convergence insufficiency only experience eye drifts when focusing up close and generally have good vision.
Functional complaints include “I lose my place when reading” or “I have difficulty concentrating on schoolwork”.
The treatment approach for most patients is to use lenses and prisms, sometimes with selective occlusion or tensor filters to alleviate some symptoms while trying to restore balance in the patient's system. In many cases the patient will use prism lenses in conjunction with in-office vision therapy. Vision therapy is a series of exercises that retrain the visual pathways that were impacted by their head injury. Because of neuroplasticity our brain is able to recreate these visual connections and relearn how to properly control eye movements, align the eyes, and process visual information.