One of the aspects of perfect eyesight Bates discovered, was movement, especially oppositional movement. He found that people with defective sight perceived that objects were stationary while those with perfect sight could demonstrate when directed, that they noticed all objects slightly swaying and that if they tried to imagine objects stationary their vision worsened. Another facet was imagination, those with perfect eyesight, had bad imaginations, especially related to visual objects and visual memory.
William H. Bates wrote:... The eye with normal vision, therefore, sees one part of everything it looks at best, and everything else worse, in proportion as it is removed from the point of maximum vision ... .
... Contrary to what is generally believed, the part seen best when the sight is normal is extremely small. The text-books say that at twenty feet an area having a diameter of half an inch can be seen with maximum vision, but anyone who tries at this distance to see every part of even the smallest letters of the Snellen test card—the diameter of which may be less than a quarter of an inch—equally well at one time will immediately become myopic. ...
The Cure of Imperfect Sight by Treatment Without Glasses(PDF link) p. 115.
What people with imperfect sight do is strain, tense and stare in attempt to see better but that just exacerbates the problem. To better your vision, you need to improve your memory of visual objects. Since you can only see such a small area best at once, the mind is a key component to vision. Bates recommends often to remember a black period, or a solid color like black in your memory and if you can do it perfectly the vision is perfect.
Another thing Bates focused on was the duality between light and darkness -- which reminds me alot of the teachings of the three kayas: Nirmanakaya, Sambhogakaya and Dharmakaya. He advocated palming:
The purpose of this is to relax the eyes by seeing nothing but blackness, which those with imperfect sight have trouble with, but practice improves this. For the other extreme of vision or adjustment to white light he advocated sun treatment. For beginners it is best to just lay or stand where you can look at the sun with closed eyelids and sway slightly back with your head and neck. When that becomes comfortable you can escalate to opening your eyes for brief periods to the sun. If you think about it is very logical and profound -- if you cannot experience black or look at the sun without discomfort or seeing imaginary "floaters", how can you possibly have perfect eyesight? Again it is alot like Buddhist teachings -- if you cannot notice the emptiness, cognizance and unity of those two, which make up the mind's essence, how can you be happy and in control?
Now I don't want to get into a big debate with skeptics. If any myope in good faith is willing to print out a Snellen eye chart, I can give you instructions to help demonstrate that the vision is variable and that it can be improved temporarily in mere moments(and with diligent practice permanently). If you have 20/20 vision you can easily demonstrate the truth of this also by trying to stare and see a large area best for a prolonged period -- which will produce strain and lowering of the vision. I would also advise people to stick to Bates' book, his Better Eyesight Magazines and the work of his assistant and wife Emily Lierman/Bates, and forget "modern Bates teachers" or other types of modern vision teachers who teach nonsense and stray from the mind-bind connection that needs to be rekindled and the unity of darkness and light.
My questions to forumers here are what are the best practices in Buddhism to:
1) Help produce relaxation especially pertaining to a body-part like the eyes?
2) Improve memory, especially visual memory?
3) Facilitate non-attachment, especially regarding the organ of sight and visual outcomes?