A monitor riser is a great tool to help you correct your posture and maintain it. Depending on the number of monitors, they are also an excellent way to preserve space when it comes to desk space.
A monitor riser will make sure that you maintain proper posture by "raising" the height of your screen enough so that you don't have to hunch over the desk any more than necessary when working. It takes very little effort for this simple change in position but can significantly decrease muscle tension throughout your neck and back. It also allows for smoother movement, prevents eye strain, as well as helps people who navigate through multiple screens at once.