People with diplopia might otherwise exhibit normal vision. Those with reading problems or concerns about learning should talk to their doctor about these problems so the doctor can properly diagnose the issue. The medical professional will administer a routine eye exam and request a comprehensive medical history that includes questions about headaches, blurred vision, and the ability to focus. NPC (near point of convergence) is a test that measures the distance from the eyes to the point where they can focus without double vision. PFV (positive fusional vergence) has the individual look at an eye chart through prism lenses.

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