I really am no authority on this subject, but I found a homemade solution that helps my eyes. They were red, dry and sore all of the time. I am in the process of doing the parasite cleanse and I have already done 5 liver flushes and the Master Cleanse 3 times for a total of 30 days.
The recipe is in the Master Cleanse book. You can find the whole book online if you look through the MC forum. I use the formula a couple of times a day. It stings, but it removes the "film" that seems to cover my eyes at times. If you can't find it, let me know and I will give you the formula.
I agree that your son sounds like he needs to follow a series of cleanses. Start with the parasite and go from there. I agree Humaworm is the best. Click on "Cleansing" at the top of this page to get started.
Also, Owen has a wonderful site. Go to the curezone google at the top right of this page and type in Owen. Then go to his home page and read everything. What a truly insightful read it is. Aloha