视觉的两项重要职能是对象识别和注意。第一部分介绍对象识别的系统过程，详细阐述视觉信号从视网膜到大脑皮层的传导转化过程，并说明了视觉系统在不同层次对视觉信号的加工处理。第二部分，首先介绍了对象识别过程与注意的相互关系以及注意的重要意义。接着综合整理了国内外关于决定选择性注意因素的种种争论，简述了其主要观点及实验基础。基于对视觉过程的理解，和国内外注意研究现状的综合整理，在文章第三部分构建了一个统一的注意模型，该模型包括注意的生物模型与注意的逻辑模型两个部分。最后基于视觉的认知理论对教学现象进行了分析，并提出一些建议。

In the first part of this paper, the vision signal transfer process from retina to cortex was presented clearly, and manufactures to the signal in every level were illustrated. Furthermore, the importance of the attention and the relationships between the recognition process and attention was discussed. In the second part, we give a summary on the biological process, models and the experimental data about attention home and broad。The augment between each point of view was analyzed. In the third part, a unified model for attention was proposed, which include the biological model and the logical model. Finally, several advices for teaching based on cognation theory were presented.