ds1 has started making very pronounced double blinks constantly, it gets worse when he's tired or concentrating but is happening almost constantly now, playschool and my dad even noticed and commented.
he doesn't seem to have anything in his eyes and can't seem to decide if their sore or not... so i'm guessing not!
We had the same with ds at the same age. I took him to the opticians to get checked out and they said it was nothing and his eyesight was fine. They said it was probably a nervous/habit thing and not to worry about it. He's grown out of it now. It might be worth getting him checked at the opticians to be on the safe side
Definitely sounds like a nervous tic. Don't pull him up on it (and persuade DP to do the same) but find out if he's feeling anxious about something - such as playschool. If it continues for a long time, or changes into another kind of tic (clearing throat, pursing lips etc) then I'd talk to your GP about it.