Reading in low light does not impair a child's vision. However, both bright and dim lighting can temporarily strain a child's eyes. When a child reads in low light or does any type of close-up work for long periods of time, it becomes harder for them to focus and they blink less, which can cause their eyes to become dry and irritated. To reduce eye strain, have your child take a break every 20 minutes or so and focus on something in the room.