在光线暗处看书真的对眼睛有害吗?

The eyes adapt quickly when going to the light -- emerging from a tunnel into the sun, say -- but going to the dark 'requires the regeneration of photo pigments, and that takes some time to reach full dark-adaptation,' says Dr. Sheedy。
希迪博士说，从暗处到亮处时眼睛适应起来非常快，比如从隧道里出来重见天日时，但从亮处到暗处时“需要新生成光色素，因此需要一些时间来完全适应黑暗”。

Adjusting to the dim light next to your bed should only take seconds. But when going from bright light to maximum darkness, studies have shown, eye sensitivity continues to change for up to 25 minutes, he says。
他说，你对自己床边暗光灯的光线的适应只需要几秒钟的时间。但有研究表明，如果从亮如白昼转到漆黑一片，眼睛的感光度要持续变化长达25分钟的时间。

Just ask a pirate。
问问海盗吧

'Ever wonder why a pirate wears patches? It's not because he was wounded in a sword fight,' says Dr. Sheedy. Seamen must constantly move between the pitch black of below decks and the bright sunshine above。
希迪博士说：“想知道为什么海盗总是戴着眼罩吗？这并不是因为他在剑战中受了伤。”真正的原因是水手必须经常在漆黑的甲板下和明亮的阳光下这两处地方之间变换位置。

Smart pirates 'wore a patch over one eye to keep it dark-adapted outside.' Should a battle break out and the pirate had to shimmy below, he would simply switch the patch to the outdoor eye and he could see in the dark right away -- saving him 25 minutes of flailing his cutlass about in near blindness。
聪明的海盗“在一只眼睛上戴着眼罩，就能保证有一只眼睛始终能适应黑暗。”如果战斗爆发，海盗必须转战到甲板下面，他只需要把眼罩换到另一边，就可以马上在黑暗中恢复视力──这样一来他就不用在近乎失明的情况下挥剑战斗25分钟了。