Known medically as diplopia, double vision occurs when one image is perceived as two distinct images at the same time. It may appear horizontally, or it may appear up and down, or even diagonally.

What types of diplopia exist?

There are two types of diplopia: monocular and binocular.

Binocular diplopia

Binocular diplopia refers to double vision due to misalignment of the eyes, often caused by weakness or restricted movement of the muscles surrounding the eye. In binocular diplopia, a patient sees double vision when both eyes are open but when they cover one of their eyes, they don’t see double vision anymore.

Monocular diplopia

The term monocular diplopia refers to double vision that occurs only in one eye. Among the most common causes of monocular double vision are refractive error, a change in the shape of the eye, which causes distorted vision, and the early stages of cataract, which cloud the lens of the eye.

What are the causes of double vision?

There are a variety of different causes for double vision and some may be more concerning than others.

Strabismus

Strabismus results in you seeing double when you have both eyes open, because your eyes are misaligned. The way it has historically been treated is by surgically repositioning your eye muscles in a manner so that the eyes are able to align properly. In less severe cases of strabismus surgery can be prevented. Vision therapy has been shown to realign the eyes without surgery. During therapy the eyes are trained to align and work together as a team, which removes the symptoms of double vision. If you were recommended surgery we recommend that you visit our office for a second opinion, as surgery is not always necessary if it's one of the milder cases and vision therapy alone can alleviate any double vision symptoms you might have. Learn more about strabismus.

Cataracts or dry eyes

You may have monocular double vision as a result of cataracts or dry eyes, or you may not be wearing an accurate prescription causing you to have double vision, or you may have an eye condition called keratoconus. Make sure you schedule a behavioral eye exam to get to the root cause of your symptoms and determine the cause of your double vision.

What should you do if you suddenly start experiencing severe double vision?

When you experience sudden double vision, which is more concerning and needs more urgent attention, it is important to rule out conditions like diabetes, high blood pressure, thyroid disease, and graves' disease. It is vital that you make sure there are no cranial nerve palsies affecting your eye muscles and therefore causing double vision. You should also check for brain tumors, growths on your eye muscles and inflammation. The first step is to schedule an eye exam right away so that we can use advanced technology such as the OCT and ERG to assess the s structures of the eye. If no clear cause is found, it's very important to conduct blood tests and get proper CT scan and MRI scans in order to rule all of that out, so we can then properly treat you.

Take our Double Vision Quiz

If you are experiencing double vision, please take our online assessment which can help you and our eye doctors better understand your symptoms.

How can double vision be treated?

Identifying the root cause of diplopia is crucial for treatment. When diplopia is caused by weak eye muscles, vision therapy or surgery can help treat it. In those cases where a certain disease is the cause of double vision, the underlying condition must be properly treated. Diabetes and myasthenia gravis are two illnesses that can lead to double vision, and there are medications that can help treat these conditions.

There are times when double vision gets better on its own, but in the majority of cases it requires active treatment such as vision therapy,  medication or surgery that will help treat the underlying cause. It is possible for double vision to be a permanent condition, but there are ways to cope with it. Diplopia can be managed with prisms, prisms are customized lenses that shift the image that you are seeing and manually realigns the images that both eyes thereby stopping the double vision from happening. Using vision therapy can help immensely to train your visual system to overcome or deal with diplopia by training your brain to control the alignment of your eyes and have your eyes work together as a team.