You asked whether exercises could improve your vision. Have you ever seen a Tibetan Eye Chart? Mine is similar to the one pictured below... 9 inches high and seven inches across with a red spot in the middle. Using it certainly does feel like it exercises your eyes. Whether it helps my vision is debatable -- I have great far vision (wonderful for bird-watching) but I need glasses for reading.
Here are the instructions on the back of my chart:
Move the eyes slowly clockwise following the outer edge of each arm of the figures, including the black spots, until the point of beginning is reached. Then repeat the same action in a counter clockwise direction.
After each cycle, blink and relax the eyes and then do 3-5 minutes of Palming. Repeat being careful to avoid eyestrain. Remember to breathe deeply & rhythmically. Try to do your exercises in natural sunlight.
Six muscles on the outside of the eyeball control its shape; four reaching fron front to back that flatten the eye, the other two belt it around the middle and squeeze it longwise from front to back. When the eyes are relaxed, these six muscles are flexible and cooperate automatically, adjusting the focal length so eyes may see both near and far.
Just as dependence on crutches weakens leg muscles, so does dependence on glasses weaken eye muscles by relieving them of responsibility.
(Palming -- put left hand over left eye, right over right, trying to achieve a perfect fit so that the hollow of the hand makes a slight vacuum pressure on the eyeball. Try to rest the elbows in your lap or a tabletop.)
<Piffka notes -- Pin the chart to a wall, middle circle at nose height.>
There are a few places that seem to sell these on the internet... mine cost $1, but that was a couple of decades ago. I suspect that these will still be much, much cheaper than what the optometrists are selling.