To improve the flexibility of your eyes, here's one exercise for you. You can stand or sit straight, then place your index finger near your face, do not get it too close, then slowly move it away from your body. Extend your arm as much as you can and keep focusing at the tip of your finger. Then bring the finger back towards the original position. You must remember to focus on the finger the entire time. Repeat this for about 15 times to help maintain eye focus and improve tracking skills.