Nystagmus is an involuntary rhythmic constant movement of the eyes.  Nystagmus is also sometimes described as "dancing eyes" or "jerking eyes".  The most common form of nystagmus occurs as a congenital (present from birth) disorder, usually affecting both eyes.  The other form of nystagmus is called acquired nystagmus and is associated with neurological disorders such as stoke or head injury oten occurring later in life.  In both types the patient is unable to fixate his/her eyes steadily on the one spot.  It is usually assoicated with other eye conditions or is secondary to visual loss.  Early onset nystagmus occurs within the first few weeks of life and is usually observed within six to eight weeks of birth.  In about 10 to 20% of cases it presents with mild visual loss not associated with another diagnosed ocular condition.

Congenital Nystagmus

Congenital nystagmus is usually pendular.  The eyes rotate back and forth evenly, although the size and rhythm of the oscillations may vary thoughout the day.  The osciallations will also vary with stress, wellbeing and in various directions of gaze.  Vision is often better for close work that at distance and many people adobt an abnormal head posture to minimise the movements and improve vision.  Nystagmus is most unlikely to worsen with agen and in fact distance vision often improves slightly through childhood.  It usually remains stable through adult life.  There is no cure for nystagmus.

Fluctuations of Vision

People with nystagmus often experience changes in their level of vision throughout the day.  This is often realted to their emotional state, fatigue, or when changing focus from near to distance objects or when one eye is covered.

The Null Point

Most people with nystagmus find a position with their head that slows the movement of their eyes and allows the best vision.  This is called a null point.  It is particularly evident when performing high demand visual tasks.  The head position can also vary but most people adopt a faily consistant head posture.

Glasses and Contact Lenses

Nystagmus sufferes are often long sighted or have astigmatism and as a result may need to wear glasses or contact lenses.  Wearing glasses will not cure the nystagmus bit will provide the clearest possible image at the back of the eye.  It has been found that in some peope the wearing of contact lenses helps to slow the oscillations of nystagmus but these are not usually perscribed until the child can handle the lenses independantly.  Only a small percentage of people find contact lenses helpful.

Implications for Schooling

- Cosmetic problems and social contact are often difficult as the constant movement of the eyes and often an abnormal head posture, make eye-to-eye contact uncomfortable for some people.
- Children should be allowed to sit at the front of the classroom and may need to be positioned to make allowance for their head posture.
- They should be comfortable with the level of light.  Glare may be a problem for some nystagmus sufferes.
- Some children will require large print and other adaptations for their low vision.
- They should have all their work on large print sheets on the desk with good contrast print.
- They should be given adequate time to do visual tasks at a distance.
- Teachers should be aware that stress during exams and tests may make vision worsen.

Vision Australia: Factsheets\Eye Conditions & Vision Strategies\Congential Nystagmus.doc, last modified 19th November 2003