Many conditions may cause double vision (diplopia) such as strabismus, orbital inflammation, including thyroid eye disease (TED), cranial nerve palsy, multiple sclerosis, myasthenia gravis, orbital injury, stroke, and brain tumor, inflammation, vascular malformation or aneurysm.
Double vision is characterized by two images that are either separate or overlapping. The double vision may vary during the day, being most distinct when the eyes are tired.
If double vision occurs when only one eye is open, it generally is due to eye problems such as astigmatism, corneal irregularity or cataract, but if double vision persists when both eyes open, but resolves when looking with only one eye, the cause may be orbital, muscular or neurological. This type of double vision is caused by a misalignment of the lines of sight of the two eyes. Diagnostic evaluation will include eye examination, sensorimotor examination and may include orbital ultrasound evaluation. Additional diagnostic studies may be indicated, including blood tests, CT or MRI.
Medical issues, such as diabetes, high blood pressure, prior strokes or heart disease, cancer, or other neurological or medical conditions may lead to double vision; therefore treatment depends on the underlying cause of the double vision.
Temporarily, vision in one eye may be blocked by the use of an eye patch or covering one lens of the patient’s glasses. In some instances, prisms may help reduce the double vision. If double vision persists when both eyes are open, surgery to adjust the position of the eye muscles may be recommended, and is generally very successful in restoring single binocular vision.