Blurred vision can be a cause of the body working hard to process what he's eating - so the body gets tired and bogged down (lethargy).
I find his situation might be related to food-combining. I have noticed for myself, while im eating fats (good and/or bad), I cannot combine this with high-sugar foods or starch products.
Fats (good or bad) will determine how fast the body will digest and metabolize what you eat - so its important to not combine fats with food that need the opposite effect.
Fats and oils combine with everything (except fruits) but should be used in limited amounts because while they won’t inhibit digestion, they will slow it down.
Hope this helps.
MedHelp's Food Diary is a great way to track for allergic reactions. As the Doctor above mentioned, it will help narrow the search ...
http://www.medhelp.org/user_trackers/gallery/food
C~
Hello and hope you are doing well.
Understand your concern. But food allergies are more likely to cause symptoms like abdominal pain, vomiting, diarrhea and sometimes skin rash. But if with repeated consumption he is manifesting symptoms, then it can be an allergen. It may help to maintain a food dairy and keep monitoring his symptoms. This will help to narrow the search and avoid them. Also, an allergy specialist might be able to help by identifying the allergen and by desensitizing.
Hope this helped and do keep us posted.
Hi and Welcome .. I wish I had an answer ..but, unfortunately not familiar with this at all ... please keep us posted ok?
C~