Having dual monitors is an ergonomic advantage that can help improve productivity and reduce the risk of pain and discomfort caused by prolonged sitting. Here are some of the reasons why having dual monitors is ergonomically better:

1. Increased productivity: Having dual monitors allows you to have multiple applications open and visible at the same time. This can help improve productivity by reducing the need to switch between windows and applications. Additionally, with dual monitors, you have more room to have multiple documents, spreadsheets, or web pages open side by side, which can help with multitasking.

2. Reduced neck and eye strain: With dual monitors, you can position the monitors to reduce neck and eye strain. You can place one monitor directly in front of you and the other to the side, at a comfortable angle. This can help reduce the need to constantly turn your head or neck, reducing the risk of pain and discomfort.

3. Improved posture: Having dual monitors can help improve posture by reducing the need to lean forward or crane your neck to see the entire screen. This can help reduce the risk of developing poor posture, which can lead to back and neck pain.

4. Increased screen space: With dual monitors, you have more screen space, which can be especially useful for tasks such as graphic design, programming, or data analysis. You can have one monitor for the main application or document, and the other for tools or reference materials.

5. Customizable ergonomic set up: Having dual monitors allows you to create an ergonomic set up that works best for you. You can adjust the position, height, and angle of the monitors to suit your needs, which can help reduce the risk of pain and discomfort.

In conclusion, having dual monitors can have many ergonomic benefits. It can improve productivity, reduce neck and eye strain, improve posture, increase screen space and allow for a customizable ergonomic set up. If you spend a lot of time sitting in front of a computer, it may be worth considering investing in dual monitors to help improve your comfort and productivity.