With worth four lights, the function of binocular simultaneous vision and plane fusion can be checked to determine whether the patient has macular suppression.

During the detection of worth four-point visual target, the right eye wears a red filter lens and the left eye wears a green filter lens. Due to the effect of spectral antagonism, the visual channel of green light in the right eye and the visual channel of red light in the left eye are closed, resulting in local binocular Division. The right eye can only see the lower circular visual target and the upper circular visual target, and the left eye can only see the lower circular visual target and the left and right circular visual target.

When both eyes are watching at the same time, if you can't see the red visual target, you can only see the left and right green visual targets, and the circular visual target below is green, which proves that the visual channel of the right eye is closed and does not participate in binocular visual activities, which may be macular suppression of the right eye. If you can't see the left and right green visual indicators, you can only see the red visual indicators, and the circular visual indicators below are red, which proves that the visual channel of the left eye is closed and does not participate in binocular visual activities, which may be left eye macular suppression.

When both eyes gaze at the same time, if you see that the circular sight mark below is separated into two circular sight marks, it is confirmed that the same target point watched by both eyes is imaged at the non corresponding point of the retina of both eyes, and both eyes cannot be integrated into a single and complete image through sensory fusion image. Therefore, binocular diplopia is a manifestation of binocular plane fusion image dysfunction.

Operation steps:

(1) complete correction of ametropia in both eyes.

⑵ add a red filter to the right eye and a green filter to the left eye to let the subject look at the worth four point visual target.

(3) distinguish and record whether the upper red visual mark and the left and right green visual mark disappear or dim.

(4) distinguish and record whether the circular sight mark below is red or green, and whether it is separated into double images.

Matters needing attention:

In monocular macular suppression patients, most of them have formed amblyopia because the visual center has neglected the vision of one eye for a long time. Therefore, the visual function of the tested person must be pre examined before examination; If the monocular vision is normal, the abnormal detection result may be incomplete macular suppression, that is, the visual target seen by monocular is dim.