Dr. Feingold studied seven children with eye disturbances including nystagmus and strabismus. The history of the first two were published in the study listed above. Both had behavioral problems as well as eye problems - one was throwing tantrums and the other was restless and talkative, but neither were frankly hyperactive.
After ten months on the diet, the first child had a marked improvement in nystagmus control and his vision was continuing to improve - from 20/300 (both eyes together) to 20/50. In June 1977, still on the diet after a year and a half, he was doing well at school without the low vision aids, he was able to participate in sports, and had no difficulty seeing the blackboard. At that time, he was given several foods containing synthetic colors, flavors, and salicylates, and observed. No change was seen for the first two days; then his vision regressed to 20/200 in each eye separately and 20/100 together, with near vision at 20/80. Going back on the diet, it took 21 days to restore his vision to what it was before the challenge test. In his case, it was also determined that foods containing benzoates, especially cranberries, were a problem.
This child had been diagnosed as having very marked nystagmus, in spite of surgery and treatment with patches over one eye at a time. The child was doing very well academically, but was overly talkative and restless; she still had enuresis (bed wetting) at age 5 1/2.
One week after starting the diet, her enuresis cleared. Her eyes didn't improve much until also eliminating white potatoes and bananas. Five months later, the eye doctor confirmed a marked improvement in perception as well as complete control of the nystagmus. At that time, the child was challenged for 5 days with a number of items containing the additives as well as salicylates. Her behavior changed - she became more talkative, more active, and fought with her siblings - but although her vision became worse, there was no return of the nystagmus.
Unfortunately, there has been very little published on the connection between diet and eye problems since Dr. Feingold's study. Thus, with hesitation, we must say that if you or your children have eye muscle disorders, the Feingold diet is worth a try, and that it may be necessary to also eliminate the benzoates (listed in our Handbook) as well as possibly white potatoes and bananas. Whether adults as well as children can be helped is not known at this time.
Among the slim pickings we have found on this subject in the research, Neuman (1978) reported that Yellow #5 caused a variety of symptoms including blurred vision, and Praputpittaya (2003) reported that MSG (noted in our Foodlists) caused dose-dependent vision deficits in rats.
A child might have 20/20 vision and be able to see clearly, but that doesn't mean that his eyes are able to work together smoothly, especially at close range. This difficulty in focussing on nearby things is called "convergence insufficiency" or CI, and it is three times more common in children with ADHD than in other children.
Dr. David Granet, a professor of opthamology at the University of California, has found that nearly 10% of children with CI had been diagnosed as having ADHD, and that 16% of children with an ADHD diagnosis had the vision problem. This also raises the possibility that children with this disorder are being misdiagnosed as having ADHD. Some of the children had also been diagnosed with anxiety disorder or depression. If you wear reading glasses, and take them off and spend any length of time trying to read under pressure without them, you might experience some anxiety yourself.
Convergence insufficiency and other vision disorders can be successfully treated with special glasses and vision therapy provided by specialists such as behavioral optometrists, who are knowledgeable in this area. As far as we know, there is no strong connection with diet.