Can allergies cause double vision?

Possibly: Allergic eyes can have a buildup of mucus, which can cause a temporary double vision in the affected eye. If eye drops do not make the double vision disappear, then allergies are likely not the cause. Some allergy medication can cuase drowsiness, which in turn can cause some people to have temporary double vision, but any new and constant vision changes should be evaluated by an eye doctor.

Allergies: Rarely. Allergies cause watery puffy eyes. This might affect the prescription, and cause a mild double vision. Conversely, a person on allergy medicine may have dry eye, which can also cause double vision.