Astigmatism
Astigmatism is a common vision condition that causes blurred vision. It occurs when the cornea (the clear front cover of the eye) is irregularly shaped or sometimes because of the curvature of the lens inside the eye.

Causes,
There are different ways to talk about nystagmus based on when and how the condition is acquired. Congenital nystagmus is present in a person from birth. The eyes swing from side to side and do not work together well.

Infantile nystagmus is also present early on. This kind of nystagmus appears within the first two or three months of life. It may be caused by underdeveloped connections between the eye and the brain.

• Manifest nystagmus means the nystagmus is present all of the time.

• Latent nystagmus means the nystagmus is made worse when one eye is covered.

• Manifest-latent nystagmus is a condition where the nystagmus is always present, but is also made worse when one eye is covered.

• Acquired nystagmus occurs later in life, usually as a result of another illness, an injury or as a reaction to medication.

You can also talk about nystagmus based on the cause of the condition. When defining nystagmus based on the cause of the condition, there are two types of nystagmus

Often a person with nystagmus will tilt their head to improve their field of vision. This allows both their eyes to look to one side, minimizing the effects of nystagmus on their vision. The point at which a person’s nystagmus is the least noticeable is known as the “null point”. A person with nystagmus may position their head so that they are always seeing the world from this null point, their point for the best vision possible.

Diagnosis
Diagnosis of nystagmus can be made with a comprehensive eye exam. By going over the patient’s history, measuring the eyes and testing how the eyes move and work together, a doctor can make a diagnosis of nystagmus. Nystagmus affects everyone’s vision differently. For example, a child with nystagmus may not notice any shakiness in their vision, while an adult with different reasons for their nystagmus may have shakiness impair their vision.

If the reasons for the nystagmus are suspected to be neurological, a CT scan or MRI scan may be necessary. Your doctor may decide your nystagmus is a result of another underlying medical condition and refer you to a specialist for a diagnosis.

Prevention
There are no known ways to prevent nystagmus.

Treatment
Treatment for nystagmus depends on the kind of nystagmus present. There is no cure for nystagmus. However, when the underlying medical conditions that are causing it are treated, nystagmus can be greatly reduced. People with nystagmus can and should still use glasses or contacts to correct other issues with their vision. Using books with large print, working in good lighting conditions and finding the optimal head position to reduce nystagmus can all help minimize the effects of nystagmus.

Advanced Treatment
In some rare cases, surgery may be recommended to reposition the muscles of the eye. This does not cure nystagmus but may reduce the amount of head tilting needed to reach optimal vision in a person with nystagmus. Botox can also be used to temporarily reduce the amount of involuntary movement in the eyes.

When to see a medical professional
Symptoms of nystagmus include: sensitivity to light, holding the head at an angle, tilting the head, shakiness of vision, dizziness and difficulty seeing in darkness. If you experience any of these symptoms, you should see an eye doctor immediately.

Always see a medical professional immediately if you have any sudden changes in vision. This includes darkening around the edges of your vision, dark spots in front of your eyes, halos around bright lights, a loss of vision in one part of your field of sight or any other noticeable change.

For more information, go the American Nystagmus Network