在农村,傍晚走路时常有人突然眼前漆黑一片不辨东西,只好在黑暗中摸索前进。待好久再看清周围的环境时,却发现自己仍在原地兜圈了。于是有了“鬼打墙”、“被鬼迷住了”等说法。如今,科学揭开了“鬼打墙”之谜,这是由于一些人维生素A缺乏的缘故。在人的眼睛里有一种感弱光的物质,叫视紫红质。它是由蛋白质和维生素A结合而成的。如果维生素A供给不足,就会影响到视紫红质的合成速度。出现在弱光线下分辨不清,或需要较长时间才能看清周围环境的症状,即夜盲症(俗称雀盲眼)。这种 In the countryside, when walking in the evening there was a sudden darkness in which one could not distinguish anything and had to grope in the darkness. After a long while I saw the surroundings, I found myself still running around. So with the “ghost wall”, “ghostly” so. Nowadays, science has opened the mystery of “ghost beating the wall”, which is due to the lack of vitamin A in some people. In the eyes of people there is a feeling of weak light material, called rhodopsin. It is made of protein and vitamin A combination. If insufficient supply of vitamin A, it will affect the speed of rhodopsin synthesis. Appear in poor light to distinguish, or take a long time to see the symptoms of the surrounding environment, namely, night blindness (commonly known as bird blind). This