The ability to control and coordinate the muscles in your eyes is extremely important to the clarity of your vision. For most of us, this is a relatively straightforward affair; our eye muscles move in sync with each other, and enable us to see whatever we want to with ease. Some individuals don’t have this level of control over their eyes; their eyes still move in sync, but repeatedly, back and forth, instead of looking straight at an object or person. This condition is known as nystagmus and leads to difficulty seeing properly.

The causes of nystagmus are diverse; more often than not, this condition appears at birth or during early infancy. Congenital (from birth) nystagmus is often coupled with strabismus, a condition in which the eyes are not coordinated. These types of nystagmus are often inherited; genetics seems to play a role in acquiring the condition. Other types of nystagmus can manifest later on in life, caused by many different triggers. Multiple sclerosis, head injuries, and brain tumours might all cause the condition; some antiepileptic medications can also cause patients to develop nystagmus. Some nystagmus is caused by abnormalities in the inner ear; if these abnormalities are resolved, oftentimes the nystagmus will disappear.

The symptoms of nystagmus manifest themselves in rather obvious ways; you can see the eyes moving back and forth rapidly instead of focusing on objects. Subjectively, the condition presents as blurry vision and reduced vision; children who developed the illness in their infancy will have a hard time discussing it because they’ve never seen the world in any other way. Adults who develop the condition, conversely, might describe the world as being shaky. To compensate for the shakiness or blurry vision, people with nystagmus will often tilt or nod their heads in order to get a clear picture.

When diagnosing nystagmus, your optometrist may use a variety of techniques, most of which will be focused on how the eye moves; a comprehensive eye exam should be sufficient to detect the disorder. Nystagmus is most often caused by some other underlying condition, so your optometrist may send you to an ophthalmologist or another medical specialist in order to try to diagnose the underlying cause.

Treatment for nystagmus varies dramatically depending on what is causing the condition. Given that the severity of the condition can increase when you’re stressed, reducing the number of stressful activities you’re engaged in can help mitigate its effects. You may be advised to stop the intake of certain drugs or medications. You may be given treatment for the underlying condition causing the nystagmus, which could eliminate the condition altogether. Other times, you may be given corrective lenses or other visual aids to reduce the impact of nystagmus on your day to day life.