so, you want me to explain the video, okey, i will try to do it quickly
Get a pen, and hold it from an arms length. Uno how you take a selfie, yes, do that and focus on the tip of the pen, the part that the ink comes off - the part that touches the paper when you write. You still here...
Don't focus too much you will hurt your eyes
The next think you do is look at an object in your room, or an object that is like 5-15 meters away from you. Example is, look at a small object in your room like a lamp or a cup or something small.
There are eye exercise apps that you can get for free from the app or play store.
They r good as well