Double vision or diplopia is a disorder that involves seeing two images while looking at one object. The two images may be side by side, on top of one another or a mix of both. Fundamentally there is a problem in the projection of the image on the retina, which falls at a different point in one eye than the other.
Double vision may be constant or persistent, it may come and go or it may occur only when looking in a certain direction. The cause of diplopia depends on whether it affects one eye (monocular diplopia) or both eyes (binocular diplopia). This may also determine the treatment.
There are cases of monocular diplopia when the problem persists even if you cover one eye: this problem is typically associated with the irregularities of the surface of the cornea or other retina and cornea problems. The binocular diplopia disappears, however, when covering one eye. Its most common cause is strabismus, but it may be associated with a neurological problem or a muscle.
Another form of diplopia is physiological double vision, which occurs when objects in the background field of vision, which are not the specific point of focus, to appear double. The brain usually compensates for this form of diplopia and therefore it frequently goes unnoticed.
Some signs and symptoms of double vision include pain with eye movements in one or both eyes, headaches, nausea, droopy eyelids, misalignment of one or both eyes (cross-eyed appearance or wandering eye), pain around the eyes (temples or eyebrows), and weakness in the eyes.
Diagnosing double vision involves an eye specialist, ophthalmologist, who will subject the patient to tests to establish whether the diplopia is monocular or binocular, other sight tests as well as additional blood tests, a CT and MRI scans.
What diseases can be associated with double vision?
The diseases that may be associated with double vision include the following:
- Retinal detachment
- Myasthenia gravis
- Graves' disease – Basedow
- Diabetic retinopathy
- Multiple sclerosis
- Corneal ulcer
- Polycythemia vera
It is important to note that this is not an exhaustive list and it would always be better to consult your doctor if symptoms persist.
What are the remedies against double vision?
The most suitable remedy in case of double vision depends on its cause and whether the double vision is monocular or binocular. The patient may require the use of corrective lenses, which can be combined with an orthoptic therapy in order to improve the condition with specific exercises. Other treatments include laser surgery, eye muscle surgery, wearing glasses, botulinum toxin (Botox), wearing an eye patch over one eye, and correcting the prisms on glasses. In more severe cases, the patient may require surgery to reposition the eyeball.
When to contact your doctor?
If the double vision is not an occasional ailment it is recommended to seek medical attention to determine the underlying causes and therefore the most appropriate remedy.