There are at least free band called Nystagmus
1) Nystagmus is an atmospheric black metal band of Fomalhaut and Mort from New Zealand.
2) Nystagmus is well known for his Sundance Records release The Immaculate Perception as well as his appearances on Sundaze and Vibraspirit 23 compilations. He also records under Anahata name.
3) Nystagmus is a belgian free improvisation duet of Farida Amadou (bass) and Tom Malmendier (drums) Read more on Last.fm