在弱视的诊断与治疗过程中,人们早就注意到行视标视力与单视标视力的意义。功能性弱视患者有明显的阅读分辨困难(Separation difficulty),这种现象也称群集现象(crowd phenomenon),这种现象随视标的密集程度的增加而趋向显著。所以行视标视力与单视标视力的测定,是鉴别功能性弱视与器质性弱 In the process of diagnosis and treatment of amblyopia, people have long been aware of the line of sight visual acuity and monocular visual acuity significance. Functional amblyopia patients have obvious reading difficulty (Separation difficulty), this phenomenon is also called the phenomenon of crowd (crowding) phenomenon (crowd phenomenon), this phenomenon tends to increase with the increase of visual target density. Therefore, the standard visual acuity and visual acuity of a single visual test, is to identify functional weakness and weak organic