When my daughter was 2.5 years old, she would come home from daycare and complain that her eyes hurt. I would look at them, they'd look fine, and I wouldn't think much of it. Until it got to the point where she didn't want me to turn on lights or anything because they made her eyes hurt and she'd cry.
So I took her to the Pediatrician, who looked at her eyes and said they looked fine and that, sometimes, children with light eyes are bothered more by light. She seemed to brush me off just a little too lightly, so I asked her for a referal to a Pediatric Othpamologist (I think that's right; it's an eye specialist), which she gave me. I wanted to be sure.
Thank goodness I went with my Mommy Gut instinct on this one. She not only was very far sighted, but she also had Strabismus, which my husband and I never noticed. She got her first pair of glasses at the age of three, and I had to buy her a special computer program for her to use to correct her Strabismus.
Thankfully, all of our hard work and effort has paid off. The Strabismus has corrected itself, and now, at the age of 11, her far sightedness has also started to correct itself.
If you think having his eyes checked would be a good idea, then it probably is. I had never known any little children with eyeglasses, so when my daughter complained that the lights hurt her eyes, I never gave it a thought that she was having issues with seeing and eye strain.
Good luck!