Is it better to have a higher or lower refresh rate for you computer?

It's best to have a high refresh rate. The higher it is, the better it is for your eyes.

When speaking of computer games, most games today have the option of enabling "Vertical Sync" or "V-Sync". This makes the game follow the screen's refresh rate. This can be a bad thing if your computer isn't fast enough to keep up with the screen's rate.