With the development of society, economy and culture video display terminal(VDT) is almost indispensable in our life.Related to long time computer use, people are experiencing a variety of ocular symptoms called the computer vision syndrome (CVS).It causes series of objective and subjective visual function changes，such as asthenopia and glare disability(GD).This article sums up researches in recent years to summarize the progress about visual quality and mechanism on VDT.