Nystagmus is the involuntary movement of the eye usually from side to side but it can occur with movement up and down or even in a circular motion. There are different types of Nystagmus - early onset Nystagmus (or congenital Nystagmus) or acquired Nystagmus.
Technically it is possible to treat a patient who has nystagmus as modern laser have very fast tracker systems that can keep up with the movement of the eye.
However, patients with this condition generally have poor best corrected vision and as laser eye treatment can only get their vision as good as can be achieved with glasses, then treatment is generally not recommended.
We would always assess each patient though on a case by case basis so it may still be worth pursuing for a definitive answer to your specific circumstances.
All eye surgical procedures carry a level of risk including not obtaining the desired outcome, through to varying levels of visual loss. Your eye surgeon will discuss the risks and benefits, including ones specific to your circumstances, at the time of your pre-operative consultation.