double vision can be the result of
wearing glasses that are too strong
looking directly into bright headlights passing other cars
eye muscles relaxed from fatigue, drugs, or alcohol
rapid eye blinking

The answer is eye muscles relaxed from fatigue, drugs, or alcohol. Double vision is usually related with alcohol and other drugs. This is often triggered by alcohol intoxication, benzodiazepines, opioids, or certain types of drugs for seizures and epilepsy. Head injuries, like concussions, can also cause double vision.