之所以要把灯调到暗, 完全是为了乘客们的安全。
航空业的绝大多数规则和做法都是以过去的事件和意外情况为基础的。它们发生后会被仔细检查。通过这些研究和考察，制定并实施了使航空更安全、更有效的规则。
当人眼从光环境移动到黑暗环境时，要经过一段时间让视觉敏感度逐渐提高，才能看到暗处的物体，即暗适应过程。经研究显示，在进入暗处的最初7分钟之内，人眼感光阈值会出现一次明显下降；在进入暗处25-30分钟之后，阈值才会下降至最低点。在飞机起飞前3分钟和降落前8分钟，飞行是最危险的，民航业内有一个专业的术语——危险十一分钟，也有人将其称为“魔鬼十一分钟”。这段时间内关闭灯光可以让人们提前进行暗适应过程，这样在出现紧急情况时，乘客能够跟随紧急出口灯光，快速找到出口。
同时飞行员也会将驾驶舱的灯光关闭，方便看到指示灯信号。
也有说法是关闭灯光是为了让飞机能够将能源集中在发动机，保证飞行平稳。
参考资料1: Why are the lights turned off during Landing and Takeoff on an airplane?
The vast majority of rules and practices in aviation are based on past incidents and unexpected situations. They are examined in detail after they occur. As a result of these researches and examinations, rules that can make aviation safer and more effective are set and implemented.
Because of this process, the motto “the rules of aviation are written in blood” is frequently used. Turning off the lights in the cabin or turning them to a very low level during landing and take-off, especially on night flights, is an application directly related to passenger safety.
When the human eye moves from light to dark environment, it needs a habituation period. During this period, human eye may not be able to see properly. During the landing and take-off stages, where flight is the most dangerous, the lights inside the aircraft are turned off and the human eye is intended to get used to the darkness.
If there is an emergency in flight at these stages, the aircraft may need to be evacuated immediately. In such an emergency, it is aimed for the passengers to follow the lights indicating the emergency exits and find the exit doors as soon as possible.
It should not be forgotten that every second counts when experiencing such an emergency.
Pilots also turn off the lights in the cockpit, especially on night flights, and adjust the lights of the instruments at low levels. In this way, it is aimed that the pilots use their eyes better in the dark and the lights do not turn on until the plane lands and reaches a certain altitude on take-off.
参考资料2: 民航科技上的魔鬼11分钟
我们有些时候会在新闻媒体上得知飞机失事的消息，细心的朋友们可能会发现，大多数情况下飞机失事都发生在起降阶段，那么究竟是什么原因导致的呢？一起来了解一下吧。
魔鬼十一分钟
在飞机起飞前的3分钟以及降落前的8分钟这两个时间段，民航业有一个专业的术语——危险十一分钟。
为什么这么说？因为在这两个时间段里，空中、地面交通流量大，飞行操作繁复，高度低，在发生突发情况时不利于飞行员作出足够准确的判断，还会遇到各种乱流切变的干扰。
而且在起降阶段，绝大多数情况下都是由飞行员通过目视加手动操作完成的，而在巡航阶段一般只需要通过无线信标台自动导航。
正是由于这十一分钟的事故率要高于其他时刻，所以也被称为“魔鬼十一分钟”。
乘坐过飞机的朋友们会发现飞机在起飞降落前会进行灯光调节，调暗或者熄灭灯光。其实这并不是为了节约成本，而是为了保证在“魔鬼十一分钟”里，发电机有充足的电力供应，同时有足够的能耗来保证飞行的平稳，使大家安全起飞/着陆。
还有一个原因就是人眼的机制，把灯光调暗可以让乘客提前适应黑暗的环境，在飞机起降后可以清楚地看到外面的状况，不会由于光线突变导致发生慌乱、出现意外。
