I see, I see, what You can't see
You know this simple game? I played it in my childhood. You'll have to guess what subject the other one has in mind. So here for you (to feel young again for at least just a moment).
I see, I see what you can't see?
And is .... RED

Already a clue?

It also has a little piece that's not so red.

And? Do You already know the answer?
Here's the solution.

I see, I see, what you can't see. And it is ... red
It's my glases!!!
(to be honest, I couldn't see them either without these :) )
and my dearest little child, did you enjoy the game?