NYSTAGMUS THAT IS PRESENT AT BIRTH (infantile nystagmus syndrome, or INS)
INS is usually mild. It does not become more severe, and it is not related to any other disorder.
People with this condition are usually not aware of the eye movements, but other people may see them. If the movements are large, sharpness of vision (visual acuity) may be less than 20/20. Surgery may improve vision.
Nystagmus may be caused by congenital diseases of the eye. Although this is rare, an ophthalmologist should evaluate any child with nystagmus to check for eye disease.
The most common cause of acquired nystagmus is certain drugs or medication. Phenytoin (Dilantin) - an antiseizure medication, excessive alcohol, or any sedating medicine can impair the labyrinth's function.
Other causes include:
- Head injury from motor vehicle accidents
- Inner ear disorders such as labyrinthitis or Meniere's disease
- Thiamine or vitamin B12 deficiency
Any disease of the brain (such as multiple sclerosis or brain tumors) can cause nystagmus if the areas controlling eye movements are damaged.