Tenotomy nystagmus surgery neither “weakens” nor “strengthens” the extraocular muscles; it is not strabismus surgery. Tenotomy effectively decreases the gain of the ocular motor plant to small, non-saccadic signals and was hypothesized to be efficacious for other types of nystagmus in addition to infantile nystagmus; it has subsequently been shown to damp various types of acquired nystagmus (pendular and jerk, horizontal and vertical) and reduce their associated oscillopsia. The eXpanded Nystagmus Acuity Function now allows visual acuity improvements to be estimated prior to surgery—something never before possible. More research into proprioceptive tension control should provide non-surgical methods to achieve the therapeutic improvements of tenotomy.