This may be a silly question but can you get dust under the glass? I have got some marks under the screen and I don't know where they ave come from. I have had a plastic screen protector on my iPad and rarely take it out of the house so it never goes in a bag to get scratched or chipped. I'v tried washing and cleaning the screen but they wont go away. I'v taken a picture but it isn't the best. The white dots are the marks on the iPad Could anyone tell me what they are?