Developmental sensory impairment: amblyopia or tarachopia?

Amblyopia is a relatively common visual disorder that affects about 6% of the population. It involves a substantial visual debility from a developmental etiology and its basis is very poorly understood. The vast majority of research to date has concentrated on the detection deficit for stimuli presented in isolation. Some of this work is reviewed and it is argued that these anomalies in detection, though interesting and useful, do not really explain amblyopia. A new approach is suggested in which discrimination tasks are employed for stimuli having the same amplitude spectra but different phase spectra. For this task amblyopes exhibit a dramatic and selective impairment.