What are the causes of double vision in adults? This is one of the most common questions I receive in my clinic when I treat neuro-ophthalmology patients who present with double vision.

First off double vision is not always seeing two of something. Occasionally the vision may appear blurry or hazy. A neuro-ophthalmologist can diagnose the causes of adult double vision.

So what are the causes?

Phoria Breakdown

Everyone is born with some misalignment of the eyes. Misalignment of the eyes causes double vision because each eye is looking at a different object. Normally, as adults our brains can align the images by correcting the small misalignments of the eye and as a result most of us do not see “double”.

That being said, as we get older or after an injury, our brains can lose that strong control of the eyes and double vision can occur. Initially, patients will claim that their double vision only occurs at the end of the day, when they are tired, had a couple drinks of alcohol but over time it can be more constant. Surgery or prisms in eyeglasses can help to correct the double vision.

Stroke or Brain Tumor

When one of the nerves in the brain that control eye movement is damaged (either from a stroke, a tumor pressing on the nerve or even an aneurysm) the nerve can decrease in function and it can manifest in double vision. Usually growing things like tumors result in patients having double vision gradually but in the case of aneuryms or strokes, it can be all of a sudden. This is an emergency and seeing a doctor immediately is important.

Microvascular loss of blood supply

In patients with diabetes, high blood pressure, high cholesterol or advanced age, there can be a loss of blood supply to the nerve supplying the muscles of eye movement temporally. This can result in the eyes being misaligned and double vision ensuing. Usually this returns over 12 weeks in most patients. Patients who don’t improve over 3 months need imaging and testing for sure.

Myasthenia Gravis

Myasthenia Gravis is an autoimmune disease where the muscles do not function normally secondary to antibodies against the muscles in the blood supply. Characteristically, this double vision is described by patients as double vision worse at the end of the day, better after a nap or after resting. Myasthenia can cause breathing problems and can kill someone so it is something that should be ruled out by all patients who complain of double vision by history at the very least.

Graves Disease

Graves or Thyroid Eye Disease is another autoimmune disease characterized by swelling of eye muscles that can cause double vision. Usually there are other signs such as bulging of the eyes or eyelid problems

After Trauma or Surgery

Patients who sustain damage to their eye socket from an injury or even have eye socket surgery can have double vision. Usually double vision after eye socket injury is manifested immediately after the injury. Imaging is required immediately. Also, all eye socket surgery carries the risk of double vision through direct or indirect damage to the eye muscles or their nerves. Sometimes after eye socket surgery for fractures, fixing the eye socket fracture can result in the eye being in a different position and double vision resulting.

All six of these causes are things that I look at when I see a patient with double vision in my office. As an orbital specialist and neuro-ophthalmologist in Denver Colorado, I look carefully at each patient to determine the cause and direct treatment as needed. Hopefull this is a good primer for patients who are experiencing double vision but most importantly they need to be seen in my office to rule out bad diseases or causes.