In recent years due to social development, scientific and technological progress, visual function requirements, many medical units have been gradually carried out stereoscopic vision examination.
Many countries in the world have long listed stereo vision as a pre-employment check, people who do not have a good stereo sense of learning and employment are greatly restricted. China in 1986, by the Chinese Medical Association Ophthalmology Society Occupational Disease Group, developed the visual function of occupational selection standards, has also been included in the standard stereoscopic vision. However, so far, the stereoscopic visual function examination is not popularized, in the primary medical units, especially with the optician who has the most contact with the patients with poor visual function, the stereoscopic visual function examination basically belongs to the blank. The reason for this is that there is a lack of professional knowledge, but the main reason is that there is not yet a simple and practical examination method that is easy to popularize and promote. Stereopsis is the highest stage of binocular monovision. Binocular monovision can be divided into three levels. Level 1 simultaneous vision, Level 2 fusion vision, and Level 3 stereopsis. In the units that have carried out the examination of binocular monovision, only stereoscopic vision is checked, not the first level of simultaneous vision and the second level of fusion vision.
There are a few medical units that also check for first-degree simultaneous vision and second-degree fusion vision, but they only check for simultaneous vision and fusion vision at a distance of thirty-three centimeters at the near distance and at a distance of five meters at the far distance, and they do not check for simultaneous vision and fusion vision at this intermediate distance. Based on the authors' clinical experience. These tests are incomplete and are not conducive to clinical diagnosis and treatment.
In order to establish a more complete set of binocular monovision three-level function of the examination, but also to facilitate the popularization of the use of primary health care units, including opticians, the authors based on their own clinical experience, research, designed a set of easy to promote the examination method, is now introduced for your reference.
The Worth four-hole (dot) lamp is an examination device with a history of more than 80 years, which is mainly used to check the presence of suppression to determine the first-degree simultaneous vision; the presence of diplopia to determine the second-degree fusion function, and to judge the eye difference and retinal correspondence of the primary eye.
If you start from five meters and gradually move closer to thirty centimeters, the projection angle will start from six point two minutes and gradually expand to nineteen degrees and six minutes, i.e., the projection site starts from the macular center fossa and gradually expands to the entire macular area such as the area of the rodless body, the center fossa, the paracentral fossa, and the macula.