Final answer:
If a monitor is placed too close or too far away, it could cause eyestrain, neck strain, and back pain, emphasizing the importance of an ergonomic setup.
Step-by-step explanation:
The question is focused on understanding what effects can occur if a computer monitor is placed too close or too far away from a user. Placing a monitor too close can result in eyestrain, as the eyes need to work harder to maintain a clear focus, leading to discomfort and fatigue.
Moreover, having to adjust your posture to see the screen can lead to neck strain and back pain due to the unnatural angles. On the other end, when a monitor is situated too far, the user might lean forward to see clearly, which also contributes to neck strain and back pain. Therefore an ergonomic setup is critical to minimize these risks.