Auxiliary examination device for visual focal length, and subjective pupil distance measuring device using the same for obtaining information about focusing ability of examinee's eyes

The invention relates to an auxiliary examination device for binocular visual focal length, which is a plate having a slit. During performing binocular vision examination, the plate is placed in front of the eyes of an examinee, and the binocular vision of the examinee may be moved in three dimensions through the slit, so that the examinee's both eyes may see the front visual target simultaneously and may autonomously pass the condition of the visual target that he saw to the examiner for adjusting the auxiliary device. Thus, the invention may obtain the information about the focusing ability of the examinee's eyes.