With enough patience, precision, and critical thinking, you can replace the lamp(s) in most LCDs. I have replaced lamps in two PowerBook G3 Pismo screens. One was dim, the other had turned pink in the corner, and it was spreading.

I'd imagine very very old LCDs couldn't be any harder. I sourced my lamps at Digikey with some help found googling. They have a huge selection. If you screen is dim or tunneling, remember this as a possible option if you trust your fine motor skills.