Dr. Lane has also found that Vitamin C is important. He has noted that low levels of dietary intake of Vitamin C are associated with increases in pressure in the eye. This increasing pressure also is associated with the visual fatigue that can result from extended periods of near work. The focusing mechanism needs adequate levels of vitamin C and chromium for efficient functioning. Adequate levels of Vitamin C are also needed to ensure the strength and structural integrity of the eyes.

Vitamin C is leached from the body by artificial flavors and ingredients and aspirin. It is generally recommended that an adult take between 500 and 1000 mg. a day, increasing the quantity during periods of high stress (including visual stress and extended periods of near range work).

Another vitamin that Dr. Lane thinks is of critical importance is folic acid, which helps the eyes to maintain near focus for longer periods of time as well as increase the eyes’ ability to absorb nutrition from the body. He thinks that folic acid should come from food sources rather than from vitamins.

Drs. Todd and Lane have focused their studies on the nutritional factors involved in maintaining the structural integrity of the eye. Another explanation for myopia, also incorporated in Dr. Lane’s theory, is that the lens has lost some of its ability to change focus, due to the constant pressure placed on it to maintain near point focus (e.g., when reading, writing, using a computer).

According to this theory, myopia occurs when the lens becomes “stuck” for near point vision and is unable to shift its focus to distant objects. Normally, the lens has the power to change its focus more than enough to compensate for individual differences in the length of the eye.

Dr. David A. Kubicek, a California doctor of chiropractic, explored the role of the lens in a research paper he wrote in 1988. This is a synopsis of his theory and his recommendations:

The ciliary muscle (which controls the focusing of the lens) is itself stimulated by both the sympathetic and the parasympathetic nerve systems of the body. Parasympathetic stimulation increases accommodation — the lens’ ability to focus on near objects. Sympathetic stimulation decreases this ability, allowing the lens to focus on distant objects. Clear vision at all distances requires the nervous system of the body to constantly balance and re-balance these two types of stimulation.

Nearsighted people, Dr. Kubicek reasoned, would lack sufficient sympathetic stimulation to bring distant objects into focus. Farsighted people, on the other hand, would show a weakness in parasympathetic stimulation.

To test his theory, Dr. Kubicek devised a simple muscular test that would tell him which system was weak for an individual. By performing only this simple test, he was able to predict — with 100% accuracy — which subjects were nearsighted and which were farsighted. Dr. Kubicek was then able to use this procedure and his knowledge of biochemistry to devise the right combination of nutrients that could promote proper functioning of the lens and thus help to improve vision at all distances.

Certain nutrients are known to increase sympathetic activity and others are known to increase parasympathetic activity. Nutrients that might be beneficial to nearsighted people would be vitamins B-2 and B-6, folic acid, niacinamide, zinc, magnesium and phosphorus, among others. (On the other hand, Dr. Lane cautions against phosphorus intake. His research indicates that what is most important is maintaining the balance in the body between calcium and phosphorus, a balance which is upset by the intake of too much animal-derived protein.)