孩子学习很痛苦，没兴趣

或者考试发挥不稳定，怎么办？

reference, Visual Secrets for School Success, Dr. Brenda Montecalvo; When your child struggles, Dr. David Cook 

If the child struggles...

Sometimes, it can be vision related. It's easier to see that they are seeing 20/20. There is more to that. Even crossed eye and lazy eyes are easy to detect, check out what other eye concerns can cause learning challenges.