First, FBI agents must be legal citizens of the United States and must have lived in the U.S. for at least three of the last five years. They must also have a clean record, with no felony or domestic violence convictions and no failures to make any child support, student loan or tax payments.
I also have double vision, especially in my left eye. My diagnosis (eleven years ago) is Sporadic Cerebellar Ataxia (unknown cause/symptoms 24/7). Several years ago, I ...I also have double vision, especially in my left eye.
There are many causes of double vision (diplopia), but sudden-onset, transient double vision is a different animal and almost always points to an underlying, very serious problem. For example, this is a possible symptom of a mini stroke (TIA: transient ischemic attack).