We can unlearn the incorrect vision habits, reintegrate the correct vision behaviors, and undo the damage of artificial corrections(glasses, contacts, surgery) and blur. Eye exercises are a scam, avoid wasting your time and hope on them.
A good way to start is to read the best books on Natural Eyesight Improvement. I have link to one of them on my website. Most people also need the teaching and support of a local NEI teacher. I also have a link to many of them around the world. I would be glad to interview one you are interested in to make sure they are teaching correct principles and not pushing eye exercises.