What is Diplopia
Diplopia is double vision caused by a defective function of the extraocular muscles or a disorder of the nerves that innervate (stimulate) the muscles. The images seen by the two eyes are fused into a single picture by the brain. If the eyes do not point at the same object, the image seen by each eye is different and cannot be fused. This results in double vision.
A transient episode of diplopia is usually of no clinical significance, indicating only a brief relaxation of the fusion mechanism of the central nervous system that maintains straightness.
Double vision is dangerous to survival, therefore, the brain naturally guards against its occurrence. In an attempt to avoid double vision, the brain can ignore one eye (suppression). Due to the brain's ability to suppress one eye, double vision can appear to go away without medical evaluation or treatment. The causes of the double vision however are very likely still present and loss of vision in one eye can occur due to lack of treatment. The loss of vision in one eye can be temporary or permanent depending on detection and treatment. It is in this way, that diplopia contributes to loss of depth perception and binocular vision, amblyopia (lazy eye), and/or strabismus (deviating eye).
Double and blurred vision are often thought to be the same, but they are not. In blurred vision, a single image seen by one eye appears unclear. In double vision or diplopia, two images are seen at the same time (one from each eye), creating understandable confusion for anyone who has it.
What are the symptoms of diplopia
Symptoms of diplopia include:
- Eyes appear "crossed," misaligned, or wander.
- Double vision
What causes diplopia
Diplopia is usually a symptom of strabismus (deviation or misalignment of the two eyes), although not all strabismus produces double vision. In this condition, movement of the eye in a particular direction is impaired due to paralysis of one or more muscles. Tilting or turning the head can sometimes overcome the double vision.
A growth in the eyelid pressing on the front of the eyeball can also cause temporary image separation by distorting the shape of the front of the eye and by causing a slight displacement in the path of light rays entering that eye (and thus variation in the points at which they are focused on the retina). Double vision may also be caused by a tumor or blood clot behind the eye that prevents the normal motion of the eyeball.
In endocrine-related exophthalmos, protrusion of the eyeballs is the result of an underlying hormonal disorder and double vision results from swelling and scarring in the eye muscles, causing abnormal alignment and motion of the eyes.
Rarely, double vision arises because of an abnormality within the eye. For example, a dislocation of the lens in the eye may result in some light rays passing through the lens and others around it, so that separate images fall on the retina of one eye.
Diplopia can also occur when viewing with only one eye; this is called monocular diplopia, or where the patient perceives more than two images, monocular polyopia. In this case, the multiple vision can be caused by a structural defect in the vision system, such as cataracts, subluxation of the crystalline lens or Keratoconus causing irregularities in the refraction of light within the eye.
How is Diplopia diagnosed
The first step is to determine whether your double vision is monocular or binocular. To do this, your doctor will ask you to cover one eye and then the other. If you have monocular diplopia, your doctor will evaluate you for conditions, such as cataracts, that could be causing the problem. You will then need to see an eye specialist (an ophthalmologist). If the problem is binocular and there has been no facial trauma, then your doctor will want to know if you have diabetes, Graves' disease or neurological disorders.
In diagnosing binocular diplopia, your doctor has to determine which eye muscles are affected. To do this, you will be asked to look at the doctor's finger as he moves it up, down, left and right. This lets the doctor see how far your eye can move in each direction. Your doctor also will cover one eye and then the other, while you focus on a target. If the doctor sees your eyes shift as the eye cover is moved, it means your eyes are not aligned properly. Prisms may be placed over your eye to shift the image, and the test repeated. The prisms allow the doctor to measure the amount or degree of your double vision when you look in different directions. This helps to diagnose the problem and monitor the problem over time. Your doctor will use the results of this exam, together with your medical history and additional symptoms, to determine if you need more tests.
For example, if your doctor suspects that you have hyperthyroidism, then you will need blood tests to measure thyroid hormone levels. If your doctor suspects that something is affecting the nerves to your eye muscles, you may need a magnetic resonance imaging (MRI) or computed tomography (CT) scan of your head to check for signs of trauma, bleeding, tumor or blood vessel malformations in the brain.
In most cases, double vision is easy to pinpoint in adults because they can describe what they are seeing. Symptoms are harder to pinpoint in children, who may not be able to explain what is wrong. Parents may notice that the child is squinting, covering on eye with a hand, tilting or turning the head abnormally, or looking sideways.
How can Diplopia be treated
The brain of a young child with strabismus (congenital, accommodative, or paralytic) learns to suppress the second, unwanted image seen by the misaligned, strabismic eye so as not to see double. Continued misalignment of the child's eyes may eventually lead to poor vision in the affected eye. The poor vision is called amblyopia, or lazy eye. Patching of the better-seeing eye in combination with the Eyerobics natural vision improvement program has proven to improve the vision in the poorly seeing, deviated eye as well as the healthy eye.
The strabismus may need to be corrected early in children to prevent amblyopia from developing. Otherwise, it may become permanent. A young child with strabismus should be seen by a physician to find the cause and to begin treatment.
The onset of double vision in adult life needs immediate investigation to exclude the possibility of a tumor, aneurysm, and/or neurologic abnormality. The double vision could be a symptom of a very serious underlying disorder that requires prompt attention and treatment.
How can Eyerobics help
The Eyerobics program is a program of eye exercises designed to address most eye disorders including diplopia by improving the function of both your eye muscles and at the same time relaxing them. The focus on improving your eye muscles enables your eyes to re-align themselves. Eyerobics has been very effective in restoring clear sight for people with diplopia as well as preventing amblyopia or lazy eye, often a result of diplopia.
I am writing you to let you know how pleased I am with your program. At first I was very sceptical as I suffer from diplopia and so far have not found a therapy which helps me to improve my condition. I was very suprised to discover my eyesight has improved tremendously after using your program for two weeks. I even went to my ophthalmologist to have my eyes checked a few days ago. Even he confirmed my eyesight has improved, but what is more important is that my diplopia is nearly gone. I only experience slight diplopia when I am very tired. Other times I keep pinching myself to make sure I am not dreaming!!
I am so grateful for your program and am happy to have given it a fair go. I do the exercises now only regularly, not daily, to keep my eyesight in shape.
Thanks again. I hope more people discover your method. I am so excited I am telling all my friends and family and I hope they will pass it on so more people might benefit.
Steve Dougal, NSW, Australia