try looking at his eyes and how he sees. my partner used to get plastic sheets of different colors, clear plastic sheets, then put them over the page. Usually yellow helped clear up the 'eye noise' that made reading difficult. Even if it doesn't cure it I think you need to try. Could be his learning style for symbols hasn't been found yet. I used to do flashcards with my classes, all the abc's in order. I would say all the different sounds for the letters (about 46 sounds if I remember ... its been a while) correctly, then they would repeat them back to me, usually in a happy chanting rhythm. We did it five times a day for two weeks, rested a week, then did it again. I never, repeat never had a kid who couldn't read independently by Christmas and here's the reason why. I was old school and didn't know it was normal to have non-readers by mid year. My kids loved the cards, we often raised the roof and had fun.
Make sure to ask questions, cut through the BS that is typical in education now and hang in there. Get this going now. As they get older, they are harder to motivate. Kids WANT to learn. They give up when they fail without help for too long. You are doing good here. Don't wait. You wouldn't wait on a broken leg, don't wait for this. Good luck, honey.
Reading is magic. It was the greatest thrill I had as a teacher to finally see my five and six year old kids read on their own. Give them the skills, rote it out until they get it, then watch them go. No one gives kids enough repetitions on anything anymore because they (the teachers now) find it 'boring' (for them). This is work but it is only work for a while. -RVdss