A team of scientists from oxford university in the uk have discovered the reason why people feel drowsier in dim lighting and more alert in bright white light .
英国牛津大学的一组科学家发现了人在弱光下更易瞌睡在强光下更警觉的原因。
It works because it teaches your body that it can 't catch up on sleep in the morning , so eventually you 'll start feeling drowsier earlier in the evening .
