Current concepts of idiopathic infantile nystagmus are summarized, with special attention to treatment and differential diagnosis of this condition. Advantages of the Anderson procedure over the Kestenbaum procedure are suggested for head turn associated with this condition, and the need for further studies is acknowledged. The importance of the extended slow phase in understanding the waveforms of infantile nystagmus is stressed. Our studies reinforce what I believe to be the natural history of infantile nystagmus, as well as the history of periodic alternating nystagmus. The critical delineation of diagnosing periodic alternating nystagmus is emphasized with respect to the type of operation to avoid overcorrection of head turns in patients with nystagmus. Continued searches for manifest latent nystagmus are important, because that condition is currently the only truly treatable nystagmus. I thank the American Association for Pediatric Ophthalmology and Strabismus for the privilege and honor of presenting the 1997 Costenbader Lecture.