Double vision is a common side effect of head injury. It occurs when the eyes do not align to the same point in space.
Today you will learn more about the causes and treatments for double vision after head injury. You’ll also learn why double vision sometimes disappears on its own and why that is not always a good sign.
Let’s dive in.
Causes of Double Vision After Head Injury
The most frequent cause of double vision after a head injury is damage to the nerves or muscles that control eye movement.
With normal vision, each eye creates its own image of the environment. To make this appear as one clear picture, the muscles in each eye help the eyes converge on a single point. The brain then combines the images from both eyes to form a coherent picture.
When the nerves or muscles in the eyes become damaged, they cannot work together to properly align. As a result, double vision and other eye problems can occur.
Strabismus and Double Vision
Sometimes after a head injury the eye muscles can become so weak or damaged that a visible deviation will occur. This condition is known as strabismus.
Strabismus causes one or both eyes to look in different directions. There are different directions the eyes might deviate in, depending on the type of strabismus:
- Esotropia. This type of strabismus causes the eyes to look inward, as if the person is always crossing their eyes.
- Exotropia. With this type, one or both eyes are looking outward.
- Hypertropia. Finally, sometimes one eye will be looking up and one eye will look down.
Any of these types of strabismus will cause double vision. However, sometimes the double vision can increase depending on which direction you look.
It is also possible that the deviation is too small to see with the naked eye. In those cases, the cause of your double vision may not be identified immediately.
Therefore, it is important to visit an ophthalmologist as soon as you start experiencing double vision after a head injury. They can determine whether eye deviation is causing your double vision.
Side Effects of Double Vision After Head Injury
Double vision is an extremely disorienting condition and can cause several secondary problems. These include:
- Difficulty walking
- Problems with balance
- Reading difficulties
- Impaired ability to perform activities of daily living
Double vision also impairs a person’s depth perception, which causes problems with hand-eye coordination. As a result, a person with double vision can appear clumsy and often knock things over accidentally.
Treatment for Double Vision After Head Injury
Treatment for double vision after a head injury can vary, depending on the cause.
For example, sometimes a head injury can cause a person to lose their blink response. This can lead to a dry cornea, which can result in double vision. If that is the case, treatment can be as simple as a prescription for eye drops.
Other common treatments for double vision after head injury include:
- Corrective glasses
- Opaque contact lenses
- Botox injections into the eye muscles
- Eye patch
- Surgery to correct eye positioning
In addition, if double vision is caused by weakened eye muscles, eye exercises may help.
Eye Exercises for Double Vision
The following are some eye exercises that can help improve your double vision:
1. Jump Convergence
For this exercise, you will need a pencil and a piece of paper with a letter written on it.
- Tape the paper to a wall on the opposite side of the room.
- Stand about 10 feet or 3 meters away from the wall
- Hold the pencil about 12 inches or 20 cm away from your face. If you see double at this range, hold the pencil farther away until your double vision fades.
- Next, focus on the tip of the pencil in your hand until the image is in focus, then look at the paper on the wall until its image is in focus. Then switch back to the pencil in your hand again
- Repeat ten times, gradually moving the pencil closer to your face until you can focus on it the whole time without any double vision.
2. Fixation Exercises
What you need: Fruit Loops or Cheerios and a pipe cleaner (a shoelace can also work, just tie a knot at the end of it so the loops don’t slip off).
- Closing one eye, hold one fruit loop in your fingers in front of your eye.
- With your other hand, insert the pipe cleaner or shoelace through the loop. Do not move the loop towards the pipe cleaner. The goal of the exercise is to keep your focus on the small hole.
- Once you get the loop on the pipe cleaner, repeat a few more times until you have a row of at least five fruit loops.
- Now, switch to your other eye and repeat.
- Once you feel confident with those exercises, try to repeat the activity using both eyes.
3. Pencil Push-Ups
These eye exercises will help improve your ability to focus on a moving object without seeing double.
What you need: One pencil. If you do not have a pencil, you can use your finger.
- Hold the pencil out in front of you at arm’s length. Keep the pencil in a vertical position with the tip pointed up.
- Move the pencil slowly toward your face, keeping your eyes focused on the tip. When you see two pencils instead of one, your eyes have stopped collaborating. Stop moving.
- Now look away and rest your eyes for two seconds. Next, look back at the pencil. If you still see double, focus until the double vision disappears and you only see one pencil again.
- Move the pencil away from your face while focusing on the tip the entire time. Then repeat.
- Each time you do this, try to move the pencil a little bit closer to your face. Your goal should be to get the pencil six inches away from your nose without seeing double.
Try to do this exercise for ten minutes per day or however long you can handle.
These three exercises should help strengthen your eye muscles and reduce your double vision. If you do not notice your symptoms improving, talk to your optometrist.
What If Your Double Vision Improves On Its Own?
Sometimes, double vision will fade on its own after some time. While this could be a sign of recovery, it is not usually a positive development.
That is because the brain can actually suppress vision from one eye to compensate for double vision. Therefore, while it might seem like your double vision has improved, in reality you now only have vision in one eye.
This is why, even if your double vision fades on its own, you should contact your ophthalmologist and schedule a visit. It’s possible that your vision is still impaired and you just do not realize it.
Understanding Double Vision After Brain Injury
Double vision occurs when the eyes cannot converge properly. This can happen after a head injury if the nerves that control the eye muscles become damaged.
Fortunately, there are many treatment options available for double vision, including corrective lenses, surgery, and eye exercises.
Talk to your ophthalmologist for more information on the best treatments for double vision after head injury.