Nystagmus is an involuntary, quick and repeating movement of the eyes. Usually, the movement is horizontal (horizontal nystagmus), but it can also be vertical (vertical nystagmus) or circular (rotatory nystagmus). The movements can vary between slow and fast and usually involve both eyes.
People with nystagmus sometimes do not feel the movement of the eyes, because what they are seeing doesn’t look unusual to them. They can bend their head to see more clearly. This helps decrease or slow down the movement of the eyes.
There are two types of nystagmus – congenital and acquired. Congenital nystagmus develops in early childhood, usually between six weeks and three months of age. Sensory nystagmus starts at the beginning of life and is connected to poor eyesight, connected to different conditions including cataracts (clouding of the lens of the eye), strabismus and hypoplasia of the optic nerve.
Some of the known reasons for nystagmus are:
- Hereditary
- Albinism
- A wide array of eye diseases including cataracts, strabismus
- Diseases such as Meniere’s disease, multiple sclerosis or stroke
- Injury to the head – this is a common reason for acquired nystagmus in younger people
- Usage of some medications such as lithium
- Alcohol or drug usage
- Issues with the ears
In some cases of acquired nystagmus, stopping some medications, alcohol or drug use can end the problem. However, nystagmus is commonly a permanent condition. It can be alleviated with some procedures. Improving eyesight with glasses or contact lenses is an important part of the treatment for nystagmus.
Eye muscle surgery can be appropriate for some people with nystagmus. It can improve eyesight, but it doesn’t completely remove nystagmus.