Inch Flashlight

Laptop screen almost completely black?

My parents tried to use their laptop today, only to find that the screen is extremely dark. They can’t remember accidentally hitting any buttons to make it do this. Everything seems to be working find, but I was having to shine a flashlight an inch away from the screen just to be able to locate the mouse cursor.
This has never happened before.
Any ideas on what may have caused it, and/or how it can be reversed?
The laptop is a Dell Latitude D510, approximately 5 years old.

The laptop might have a pair of function keys made to increase and decrease the screen brightness. Check for those; they might look like this: ^ and the other one aimed down. Otherwise, the back light may have burned out. My suggestion: get a new laptop.

Parilament – Flashlight (12 Inch Extended Version)