Does he have good posture when he reads, or does he bend his head around, look at the book from an angle, hold his head close to the book etc? If he doesn't do any of those, I'd most likely guess vision isn't the issue.
He doesn't do any of these things. OTOH, he doesn't sit up nicely and read. He is almost always lying down. He is a chronic leaner and flopper as well. He will still want to sit on my lap at any lengthy event so he can flop all over me. Though he is not your classic "boy who can't sit still" (not "hyper"--he will sit quietly and read or play chess in a room full of kids running around and screaming) he also is not stationary for long, constantly readjusting his body to lean, flop, rest and lie prone in new ways.
I will try the pencil test. I asked him yesterday if his eyes ever bother him, if anything is ever hard to see, blurry, hard to focus on, etc and he looked at me like I was insane...but IDK if kids know when they have these issues.
Re reading, he does skip/substitute small words sometimes or lose his place, but last years he was tested at 190 correct words per minute (age 6) so he's doing pretty well! He LOVES to read...it's his world.
