If you can already reasonably well focus sharply, and also have no difficulty with the coordination of both eyes, you can now do the last step towards perfect vision.
Just take a text on paper - the print quality should be very good - and move the page as near to your eyes, as you just see the characters sharply and can recognize them clearly.
Then again slowly move the text away, and than again toward you etc. And do not forget, you need lots of light for the exercises. Best if its sunlight.
Book covers, with their contrasting headlines are very well suited for the exercise.
If you can read the text with outstretched arms, you are on the right track. Now take the next smaller text size for exercise.