• are aged 18 - 40;

• have suffered a mTBI according to VA/Department of Defense (DoD) criteria with documented evidence of alteration of consciousness (AOC) \< 24 hours or loss of consciousness (LOC) less than 30 minutes;

• were injured between 1 month and 15 years ago;

• received a Glasgow coma scale (GCS) score of between 13 and 15 upon emergency department (ED) admission, if available;

• experienced less than 24 hours of post-traumatic amnesia (PTA), if any;

• have ongoing post-concussive symptoms as evidenced by a score of 18 or greater or a score of 2 or greater on question 6 (vision problems, blurring, trouble seeing) on the Neurobehavioral Symptom Inventory (NSI);

• have ongoing vision-related symptoms as evidenced by a score of 31 or higher on the Brain Injury Vision Symptom Survey (BIVSS);

• have PTCI as evidenced by obtaining a score of 21 or higher on the convergence insufficiency symptom survey (CISS), a specific measure of convergence insufficiency;

• are fluent in English; and

⁃ have been on stable doses of any vision-altering medications for the past 2 months.

⁃ Stereopsis of 500 sec arc using Randot Stereo Test.

⁃ Exophoria at near 4 prism-diopter (PD) or greater than magnitude at distance

⁃ Near point of convergence (NPC) \> 5 cm

⁃ Convergence amplitude at near \< 15PD break or the Sheard criterion not met

• are aged 18 - 40;

• CISS score of 20 or lower;

• near point of convergence (NPC) \< 6cm; and

• positive fusional range \>15 prism diopters.

• Stereopsis of 500 sec arc using Randot Stereo Test.