In an Editorial published in the August 1994 issue of the Archives, Dr Kushner1 expressed concern that because recently introduced tests underestimate the severity of the deficit, clinicians are being misled and the needs of the visually impaired child are not being met. Our response focuses on preferential looking-based tests (acuity card procedures [ACPs], including Teller Acuity Cards), although certain comments are relevant also to electrophysiological tests.
One factor is the "low sensitivity [of ACP] for detecting subnormal visual acuity"1 due to the wide normal range in infancy. Consequently, compared with letter-based tests such as the HOTV test (Good-Lite Inc, Chicago, Ill), ACP is a "functional" technique.2 Two points militate against this view. First, the normal range of ±1 octave, does not change significantly across the first few years of life,3,4 and this cutoff differentiating normal from abnormal is identical for ACP and for letter-based