Unfortunately, haven't heard of anybody repairing the LCD panel itself, or know of a way to check into it more, so expect the panel just needs to be replaced.
It really depends on your situation if you want to change the display since factors include cost, how much longer you plan to use this notebook etc.
Everyone is different and I may be a little biased since I work for ASUS, but if possible, put the money towards a newer system if you can afford it rather than an out-of-warranty system that may eventually have other things wear out or go bad (like the fan, hard drive, battery, etc.).
If you didn't already know, you can get an external USB hard drive housing to transfer your data to a different system if this makes any difference.
Also, consider converting this system for stationary use with an external monitor like a desktop if it makes sense.
Yes, if you decide to fix it, find someone you can trust to do a good job at a reasonable price, but any competent tech should know the problem is with the LCD screen if you want to test or check with them before letting them fix it.