May I ask if your son has problems with words jumping on the pages of books? Computers? etc...Or does it only happen when he is copying from the chalkboard? If he is having trouble with words jumping from other text, you might want to try colored tablet paper (usually legal pads come in colors). There is also a vision screening that can be done to determine if this is happening and colored overlays can be given for students to use. This might be something to look into to help him. Not a diagnosis..just a suggestion.