I too thought the "diet layer" has been addressed before getting to this point - it serves little purpose tweaking a protocol without taking care of the primary portion: diet and cleansing.
You can't expect to get rid of toxins (aka getting back to health) while your dumping toxins into your body (aka mcdonalds/wendys/chinese foods).
He may very well be sensitive to additives and preservatives in the food - for example msg can very well be the culprit for his symptoms (there is research on msg affecting vision).
A complete overhaul of the current diet has to be achieved so that the basic foundation of "back to health" protocol is accomplished. It could be as simple or as complicated as this diet change to get rid of offensive toxin, it all depends on his willingness to change his current lifestyle.