The default text size on iMac computers is 12 pt., which can be difficult to read if you are far-sighted or suffer from other vision disorders. Rather than squint while reading, permanently increase the size of text on your Mac through the window's properties. The properties menu allows you to choose the best text size, and remembers the configured information to keep the font size the same even after closing the window.
Click the "Finder" icon. Click "Macintosh HD." Press "Command + J" on your keyboard to open the "View options" menu.
Click the "Text size" drop-down menu. Click a larger size in the menu.
Drag the slider in the "Icon size" section all the way to the right until it is at 128 x 128.
Click the red button in the top-left corner to save the changes and exit.
Click "System Preferences," "Displays."
Click the "Display" tab. Click a lower resolution size in the "Resolutions" menu. The screen automatically changes to the new resolution, and asks if you want to keep the resolution. Click "OK" in the pop-up dialogue box to save the resolution settings.
Click the red button in the top-left corner of the window to close the preferences.