应用普通双目间接检眼镜可在被查瞳孔区内获得如图1所示的三个倒象。图中1、2是检查者的两瞳孔通过观察系统及物镜形成的象,3是光源经聚光镜及物镜形成的象,这三个t倒象必须位于被查瞳孔内。一般1、2之间的距离b固定为3.5mm,如被查瞳孔直 The application of ordinary binocular indirect ophthalmoscope can be checked pupil area as shown in Figure 1, the three inverted image. Figure 1, 2 is the examiner’s two pupils through the observation system and the formation of the objective lens, 3 is the light source formed by the condenser lens and the object, the three inverted image must be located in the pupil being checked. General 1,2 distance b fixed at 3.5mm, such as being checked pupil straight