Double vision, also known as diplopia, is a condition where a person sees two images of a single object when looking at it. Double vision can be caused by a range of conditions, including problems within the eye, such as the cornea or lens, muscles or nerves controlling eye function and movement, or issues in the brain. Here are some common causes of double vision:

• Cornea problems: The cornea is the clear layer that covers the front of the eye. Problems in the cornea distort its surface, which can create double vision. Such problems include astigmatism, dry eyes, and keratoconus.

• Eye muscle problems: Eye muscle problems can cause double vision, including strabismus (misaligned eyes), a weakened or paralyzed eye muscle that prevents the eyes from aligning properly.

• Nerve problems: Certain cranial nerves connect the brain to the eye muscles to control eye movement. Some conditions that can affect or damage these cranial nerves and lead to double vision include diabetes, multiple sclerosis, Guillain-Barre syndrome, and myasthenia gravis.

• Brain problems: Several areas inside the brain process visual information that is transmitted from the eyes. Brain problems that can cause double vision include a brain tumor or aneurysm, stroke, and giant cell arteritis.

• Other causes: Other causes of double vision include Graves disease, a thyroid condition that affects eye muscles, and cataracts, a clouding of the normally clear lens due to aging.

Double vision can be classified as either monocular or binocular. Monocular diplopia is present when you use only one eye at a time, and it may appear as a shadow. Binocular diplopia is present when both eyes are open at the same time, and it goes away if you cover one of your eyes. If you experience double vision, its important to see your healthcare provider right away, even if its caused by something as simple as needing new glasses.