Caves and mines are dark, so light is definitely the single most important problem to solve when you want to enter them. Light is such an important topic we started to sort the different aspects into groups, to make them easier to understand.
The use of light by speleogists is important, and actually a rather young problem. Real scientific cave research started only 150 years ago. And since then the lights used for caving were continually developed. While we all depend on scientific and industrial development, the cavers always tended to customize available technology for their needs.
Show caves have different requirements for light than individuals, becuase the light is installed and not mobile. On one side the energy is available in large amounts, as it is possible to install cables. On the other hand the light must burn for a long time, must be easy to handle, and should require a minimum of maintenance.
Mining is much older than cave exloration. It actually started in the prehistoric times. Miners used candles and oil lamps in various versions. Those were the only available light sources, and the fuel was easy to harvest. Later the needs of the mines pushed the development of new light sources, like carbide lamps, but also the security problems related with mines. For example, for the use in coal mines security lamps were developed, which did not ignite possible explosive gases.
This is the rest, anything which does not fit into above three categories.