Double vision, also known as diplopia, describes the phenomenon of seeing a double image of something, while there should only be one actually.
A person suffering from this condition can view the two images either side by side or one on top of the other, whereby the perception of balance, movement or reading ability are disturbed.
Double vision is referred as ‘Monocular Diplopia’ when it affects only one eye, while in case of both eyes being affected, it’s called ‘Binocular Diplopia’.
Double vision treatment mostly depends upon the underlying cause and type of the condition, but it can possibly involve exercises, specifically designed glasses and surgical options.
What Causes Double Vision?
From very benign to life-threatening ones, dozens of causes exist for double vision. Therefore, it is quite imperative to get your eyes examined by a professional eye doctor, who must consider your history, in addition to performing a detailed examination to determine the underlying cause for initiating the right kind of treatment. In fact, emergency treatment might be needed in some cases as well.
Causes of Binocular Double Vision
‘Strabismus’ or ‘Squint’ is considered to be one of the most common causes of double vision – a condition, which disturbs the alignment of the eyes. It is commonly found in children. However, the presence of strabismus doesn’t always lead to diplopia.
Other conditions leading to diplopia can include:
Located in the neck region, one of the functions of the thyroid gland involves producing a hormone named ‘thyroxine’. The external muscles controlling the eye can undergo various changes due to thyroid malfunction, which include “Grave’s Ophthalmopathy” – a condition leading to the protruding of the eyes because of fat and tissue build-up behind them.
Stroke or Transient Ischemic Attack (TIA):
One of the major implications of a stroke is the inability of blood to reach the brain, also affecting the nerves controlling the eye muscles, possibly leading to double vision.
A condition leading to a bulge in a blood vessel inside the brain, which can lead to extra pressure on the nerve of the eye muscle, turning into a possible reason for double vision.
It can not only affect the blood vessels supplying blood to the retina at the back of the eye, but also the nerves responsible for controlling the movement of the eye muscles.
Muscle weakness is one of the major symptoms of myasthenia gravis, also including the ones needed to control eyes.
A tumor in the brain can create a growth behind the eye, which can sometime inflict damage upon the optic nerve, possibly hindering with the free movement of the eyes.
Also referred as ‘MS’, this disease involves damage to the central nervous system, which also includes nerves in the eyes.
Any type of physical damage to the brain including muscles, nerves or sockets of the eyes can cause issues in the movement of the eyes, a possible cause of double vision.
Causes of Monocular Double Vision
The presence of double vision in only one eye is referred as ‘monocular double vision’ –relatively less common than binocular diplopia. It can be caused by the following reasons:
It can cause monocular double vision because it leads to an irregularly shaped cornea with two curves on the surface, more like a football, while it should be perfectly round like a basketball.
When your eye is unable to produce enough tears, or tears start drying too quickly, your susceptibility for double vision increases.
Due to this degenerative eye condition, cornea becomes too thin and cone-shaped, increasing your risks of diplopia.
For example, macular degeneration, which slowly fades out the central vision of a person, also producing a swelling sometimes, leading to double vision in one eye in most of the cases.
More than half of the population of the U.S over 80 ends up with cataracts, sometimes also causing diplopia in one eye.
Double Vision Symptoms
Double vision can occur without any symptoms sometimes, while in some cases, you might observe some symptoms depending upon the underlying cause. These can include:
Unaligned eyes (one or both), also refereed as “wandering eye” or sometimes “cross-eyed” appearance
Pain caused from the movement of eye(s)
Pain in the areas adjacent to the eyes, like eyebrows or temples’
What is Temporary Double Vision?
Yes, there’s a thing like temporary double vision, and as the name suggests, it sorts out over time. Its causes include factors like alcohol intoxication, opioids, benzodiazepines, and various medications meant for seizure and epilepsy might also lead to temporary double vision. Moreover, it can also be caused by head injuries and concussions.
It’s advised to seek medical attention as soon as possible if normal vision does not return quickly enough.
Double Vision Treatment Options
The underlying cause is of significant importance while treating double vision, based on which the treatment is tailored. In many cases, treating the underlying condition also caters to the treatment of double vision.
For instance, when refractive errors like myopia, hyperopia and astigmatism are the causative agents behind diplopia, it can be fixed using glasses or contact lenses.
In case of dry eyes, artificial tears, punctual plugs, anti-inflammatory drops, warm compresses and a host of other treatments prove helpful.
For most of the corneal irregularities, medication, laser or surgery is resorted.
Binocular double vision is sometimes caused by certain vision-threatening or life-threatening conditions, for which urgent medical treatment is advised. For example, head trauma, aneurysms, stroke and other neurologic conditions.
Diabetes disrupts the blood supply to the nerves involved in support functions of the eyes, and the resultant diplopia can be cured as soon as the blood sugar levels are managed.
If scarring restricts the eye muscle movements (in case of Grave’s disease, for example) or entrapment (resulting from traumatic orbital bone fracture), surgical treatment of muscles or surrounding tissues is likely to fix the problem.
Using specially designed prisms can help with correcting intermittent binocular diplopia, caused by ‘Convergence Insufficiency’ or inability to rightly align the eyes on a nearby object. Certain eye exercises like pencil pushups can also be helpful in such cases.
Regular eye exam remains one of the most effective ways of staying away from various eye conditions and sight-threatening eye diseases. So, make sure you don’t skip yours and if you are unfortunate to encounter an eye problem like double vision, immediately seek professional help to be able to enjoy a healthy gift of sight as long as possible.