Collewijn H, van der Steen J, Steinman R M
J Neurophysiol. 1985 Jul;54(1):11-27. doi: 10.1152/jn.1985.54.1.11.
Eye movements associated with eyelid closure were recorded in human subjects with search coils, embedded in self-adhering scleral annuli, in a magnetic field. In contrast to classical notions, voluntary as well as reflex blinks were consistently accompanied by transient downward and nasalward movements of both eyes with amplitudes 1-5 degrees. These eye movements had a shorter duration than the upper lid movements, and the shapes of the spatial trajectories of eye and lid movements were not similar. The trajectory of the eye movements was only modestly affected by gaze eccentricities up to 15 degrees; there was a tendency for the downward component to be enhanced by looking upward, and vice versa. Restraining of the lids of one eye in the open or closed position did not significantly alter the eye movements during (attempted) blinks. Velocity-amplitude-duration relations of the down- and upward components were similar for the same eye before and after closure and for the closed eye and the contralateral unrestrained eye. The velocity-amplitude-duration characteristics of saccades were also unaffected by prolonged closure of the lids of one eye. Prolonged, voluntary closure of the lids was followed by a slow, tonic ocular deviation, which was consistently upward in half of the subjects and consistently downward in the other half. Additional horizontal components were highly variable even within subjects. In one subject the downward deviation was converted into upward deviation when lid closure was mechanically impeded. We conclude that elevation of the eye ball (Bell's phenomenon) does not occur during short blinks and only in about half of the subjects during voluntary unrestrained prolonged lid closure. Our evidence does not support the possibility that the transient eye movements during blinks are caused primarily by a mechanical interaction between the lids and the eye (or the scleral annulus). More likely, they are a secondary effect of an active cocontraction of extraocular muscles that primarily results in retraction of the eye.
通过嵌入自粘性巩膜环中的搜索线圈，在磁场中记录了人类受试者闭眼时的眼球运动。与传统观念不同的是，无论是随意眨眼还是反射性眨眼，双眼都会持续出现幅度为1 - 5度的短暂向下和向内运动。这些眼球运动的持续时间比上睑运动短，且眼球和眼睑运动的空间轨迹形状并不相似。眼球运动轨迹仅在注视偏心度高达15度时受到适度影响；向上看时向下分量有增强的趋势，反之亦然。将一只眼睛的眼睑固定在睁开或闭合位置，并不会显著改变（尝试）眨眼时的眼球运动。同一只眼睛在闭眼前后以及闭着的眼睛和对侧未受限制的眼睛，其向下和向上分量的速度 - 幅度 - 持续时间关系相似。单眼长时间闭合也不会影响扫视的速度 - 幅度 - 持续时间特征。长时间的随意闭眼会导致缓慢的强直性眼球偏斜，在一半受试者中持续向上，在另一半受试者中持续向下。即使在同一受试者内，额外的水平分量也高度可变。在一名受试者中，当机械阻碍眼睑闭合时，向下偏斜会转变为向上偏斜。我们得出结论，在短暂眨眼期间不会出现眼球上抬（贝尔现象），仅在大约一半的受试者中，在随意无限制的长时间眼睑闭合期间会出现。我们的证据不支持眨眼期间短暂眼球运动主要由眼睑与眼球（或巩膜环）之间的机械相互作用引起的可能性。更有可能的是，它们是眼外肌主动共同收缩的次要效应，主要导致眼球后缩。
