[Effects of head down tilt on intra-ocular pressure, near vision, and visual field and the protection effect of Chinese herbs].

Objective. To observe the influences of 21 d head down tilt (HDT) bed rest on the intra-ocular pressure, visual field and near vision in human and to study the countermeasure of Chinese herb against weightlessness. Method. Ten subjects were randomly divided into control group and Chinese herb group. -6 degrees HDT was used to simulate weightlessness. Intra-ocular pressure, near vision and vision field were measured before, during and after bed rest in both groups. Result. Intra-ocular pressure and near vision showed a wave-like decrease change during bed rest, and there exists a certain coherence between them. Visual field showed no obvious changes. Taking Chinese herb was able to antagonize the decreasing of intra-ocular pressure and near vision during various phases of bed rest. Conclusion. 1) Bed rest could lead to the decreasing of intra-ocular pressure and near vision; 2) Taking Chinese herb was able to antagonize the negative influences of bed rest on visual function.