If we use our finger pointing to screen as a habit
, the special martial coated on the screen may be destroyed by our fingernail or other pointed stuff. Though we can stick a protective film on the screen, it's a bad habit to point to screen with your fingernail. Everyone expects his computer can be used for longer time. So we have to take steps to have our LCD screen in a safe working environment. Remember that never use your finger pointing at the screen.