The tendency of the human eye, in a featureless visual field, to focus to a distance of only 1–2 metres.
1960s; earliest use found in Frederick Ira Ordway (b. 1927).
英语词典包含464360条英英释义在线翻译词条，基本涵盖了全部常用单词的英英翻译及用法，是英语学习的有利工具。