Hold your thumb at arm's length and slowly move it toward the bridge of your nose while keeping your eyes focused on it. If it doubles, reset by looking away. This eye-brain coordination drill trains convergence and signals your brain to relax neck and shoulder muscles.
We're going to strengthen that movement with either a pen or your thumb. All you're going to do is take your thumb and stick it right out in front of you. You're going to keep your eyes right on the thumbnail, and you're going to bring that towards the bridge of your nose. So as you come in, you want to make sure it stays clear that you see one thumb. If you see two, you're going to stop at that point, and you're going to look off into the distance. Reset and try it again. Keep bringing that thumb in, trying to see one thumb and see it clearly, and then pop your eyes off to something in the distance when it starts to split into 2. By doing this, you are teaching your eyes and your brain how to control that movement with your eyes coming in, and in turn, that should allow the brain to feel more relaxed in that position and relax the muscles in the shoulder and neck.
Stop Stretching Your Neck. Try This Instead (It Might Improve Your Vision Too)
