Usually you can't 'turn a window' as they are set in place. Perhaps you mean to 'pull down the shade' or 'close the curtains'? Can you please shut the curtains? The sun is shining right in my eyes. Can you please lower the shade? The sun is shining right in my eyes.

Many windows do indeed turn, as they are mounted on hinges or some other device. My grandmother's house had windows in the kitchen that pivoted open or closed by turning a handle, a bit like old car windows. If thats what you're talking about, I think you're sentence is alright for that context. Normally we'd say "Help me open/close the window." , but because you are talking about reflections off of the glass, that wouldn't be the best sentence for you're meaning. "You could also say "Help me move the window"

Thank you Lan de Vries, now I got it. I thought that the verb shine couldn't express the reflctions off of the glass. I used the verb reflect to try to make myself understood.

Could you turn the window a little because the sun is shining right into my eyes. Of course it is polite to say please