ASUS laptop screen has dark spot on screen

I use an ASUS laptop that is not very old. I noticed the other day that there was a dark spot on the screen, almost near the top right hand corner. I restarted the laptop, cleaned the screen, and nothing will make it go away. I have not dropped or hit anything off of the laptop. I'm out of ideas for troubleshooting this annoying issue. Can anyone assist? Thank you.
