Cynader M S
Hum Neurobiol. 1982 Mar;1(1):35-9.
Amblyopia, a Greek word meaning "blunt sight" refers to a common clinical condition characterised by lowered visual capacities in one or both eyes. Several different types of amblyopia have been defined and in the most common forms, strabismic and anisometropia amblyopia, one eye finds itself at a severe disadvantage relative to its counterpart. The evidence to be presented in this article will show that the reduction of visual capacities in one eye results from competition between binocular inputs rather than simply reflecting disuse of one eye. In addition, evidence will be represented to show that this binocular competition occurs in the visual cortex rather than in the periphery. In fact, there appear to be at least two separate levels of binocular competition within the visual cortex. Under most circumstances, it is possible to induce or to reverse amblyopia only during a well-defined sensitive period early in the life of the organism. With special efforts, however, prolongation of this sensitive period can be achieved and plasticity of cortical ocular dominance maintained into adulthood.
弱视，一个希腊词，意为“视力钝挫”，指的是一种常见的临床状况，其特征是一只或两只眼睛的视觉能力下降。已经定义了几种不同类型的弱视，在最常见的形式中，即斜视性弱视和屈光参差性弱视，一只眼睛相对于另一只眼睛处于严重劣势。本文将呈现的证据表明，一只眼睛视觉能力的下降是由于双眼输入之间的竞争，而不仅仅是一只眼睛未被使用的反映。此外，将展示证据表明这种双眼竞争发生在视觉皮层而非外周。事实上，在视觉皮层内似乎至少存在两个独立的双眼竞争水平。在大多数情况下，只有在生物体生命早期一个明确界定的敏感期内才有可能诱发或逆转弱视。然而，通过特殊努力，可以延长这个敏感期，并将皮层眼优势的可塑性维持到成年期。
