If you run Ubuntu 11.04 on a screen with huge resolutions, then some users with vision difficulties will find it hard to distinguish characters displayed on screen.
Fortunately, Ubuntu allows its users to increase text size displayed in windows, programs, web browsers, etc.
To change font size under Ubuntu 11.04, follow these instructions:
1. Right-click on an empty space on your desktop and select Change Desktop Background.
2. Open the Fonts tab and click Details.
3. In Resolution, increase the number of dots per inch for the text resolution with any value of your choice, the text size will increase in real-time. When you finish your adjustments, click Close.