Vision is the sum total of sensation, perception, and conception. Mechanically speaking, your retina has about 126 million light-sensing cells that produce some billion images every single minute. The brain cannot possibly assimilate all those images to create a picture, so it selects basically determining how much of a picture you will and will not see. How clear or how poor your vision will be is largely a function of your brain.
Western medicine tends to ignore the complex interactions between eye and brain. Medical training puts greater emphasis on treating the symptoms. If you have cataracts, doctors will remove the lens. Else if you have high pressure in the eye, they will alleviate it. If you see poorly, they will give you glasses. They do not tend to go deeply into the causes of these conditions.
Yet nearsightedness, for example, is clearly the result of mental stress and the fact that your brain conceives of the world as a fuzzy place. Most children who become nearsighted do so at about third grade, when the initial excitement of learning has subsided. And they begin to glimpse the unchanging pattern of school years ahead of them. Those who do not get glasses in third grade generally get them in college, when the future is not clear and seemingly endless studies lie ahead.
Farsightedness, on the other hand, tends to develop in our forties and fifties. When most divorces happen and when people ask themselves, “Could I live my life differently?”. There is no question in my mind, after nearly thirty years of working with all kinds of vision problems, that your eyesight is truly a part of your mental state. Helping your eyesight is not simply an issue of getting rid of your glasses. But of dealing with your total being: your mental, emotional, and physical state in its entirety.

the lens changes shape, becoming more spherical
Causes of Poor Vision
Vision problems usually manifest as lack of clarity in either near or distant vision. The physical act of seeing things close up is different from that of seeing things in the distance. Consider, for example, how a camera works. When light rays from the object you are photographing reach the cameras lens, they need to converge and focuses on the film behind the lens. To focus, you change the distance between the lens and the film until it is just right. Otherwise the object will not focus exactly on the film and the photo will be a blur.
In the same way, your eye needs to converge light rays from the object you are looking at and focus them behind the lens. Instead of film, you have a retina: a network of nerve cells that translates the light rays into neural information. The data are sent through the optic nerve to the brain. Where a camera changes the distance between lens and film, the eye changes the shape of the lens instead.
When the ciliary muscles that hold the lens in place are relaxed, the lens is relatively flat and allows for distant vision. When the object you are looking at is closer than twenty feet away, those muscles contract, and the lens assumes a more spherical shape. This process is accommodation (see fig. a).
Another factor thought to determine how a person sees is the shape of the eyeball. Irregularly shape of eyeballs are the cause of the two most common vision problems: myopia and hyperopia. Myopia (nearsightedness) means the inability to see distant objects clearly, caused by an eyeball that is too long from front to back. This shape makes it impossible for the lens to focus the light rays from distant objects onto the retina (see fig. b). However, it can focus the rays from close objects. Hyperopia, or hypermetropia (farsightedness), refers to the inability to see close objects clearly. Here, the eyeball is too short from front to back. Light rays from a distance focus correctly, but the lens is unable to bring the rays together before they reach the retina. If they were capable of passing through it, the rays would probably focus behind the retina (see fig. c).

from front to back. The lens can not focus distant objects
onto the retina, creating a blurry image.

from front to back. The lens focuses close objects beyond
the retina, creating a blurry image.
These descriptions explain the mechanical conditions underlying poor vision. But what causes these physical changes to occur? In one word, the answer is stress. The eyes are as susceptible to stress as is any other part of the body, and they subject to at least as much of it. Two components of visual stress prolonged, unrelieved near focusing and tasks with high-level cognitive demand often coincide in school and office work. The advent of computers has compounded the problem, creating a visual/postural repetitive strain condition called computer vision syndrome (CVS).
Symptoms include eyestrain, general fatigue, neck and shoulder pain, dry eyes, and difficulties in focusing. The computer screen is itself a visual stressor. Since the eye can never determine the focal length of computer pixels. It plunges into a visual limbo in which the ciliary muscle continually quivers with unavailing effort. The visual stress of CVS tends to bring on myopia or make it worse.
Many of our actions and reactions as well as much of our memory are guided by mental pictures, including conscious and subconscious images of events that shapes our emotional makeup. Our eyes are stressed even when we are perceiving these only “in the mind’s eye.”. All of these events take place in the brain, of which the eye is an integral part.
Because of all this, and also because we use them for just about everything we do, our eyes respond strongly to our thoughts and emotions. Because they work so constantly and so hard, they are also extremely sensitive to physical pain and fatigue. Poor vision arises from a complex interplay in the bodymind. This is why, when we begin working to improve our eyes, we need to approach this work from every possible angle. Therefor, in the process of doing so, we discover things about ourselves that we may never have suspected.