If you do not like to stay in the dark in Minecraft 1.7.2, take a flashlight or better a portable lamp.
Lantern Mod 1.7.2 and 1.7.10 is a fairly simple mod that adds two kinds of portable lamp to Minecraft, so you can explore the caves without having to use torches. This mod was created by the Cave-Gen mod?s author, in order to complete this one but later on he decided separate the lamp of the mod in case someone wanted to use only the lamp, but not the mod.

Detail and Download here : Lantern Mod

Homepage: Mods for Minecraft