DD "squinting"/screwing up her eyes

[Clure]

My DD has just started school. In the past week and a bit we've noticed her really squinting her eyes - like a really hard pronounced blink. She seems to have periods when its worse and others when she's not doing it. Doesn't really seem to be a pattern.
She has a nasty cough and full of cold and the moment, I'm not sure if she has itchy or sore eyes.
When I ask her she can't tell me, like as if she doesn't realise she's doing it.
I have an optician appoinment but its not till next monday. Just wondered if anyone can shed any light? thanks

Is it in bright light. According to our optician dd is very sensitive to light and she screws up her eyes a lot.

a friend suggested a tic, its possible - maybe she's bit anxious still settling in at big school. The light sensitivity has also made me think.... thanks ladies. Hopefully optician can put my mind at rest too.