The ability to hold ctrl down whilst scrolling up to zoom in and down to zoom out on your mouse or touchpad used to be enabled by default on OS X. Seemingly, since Lion’s release, this feature appears to have been disabled by default.
Though this is not an essential feature, and is one that can be replaced by keyboard shortcuts (⌘ + ⌥ + 8, then hold ⌘ + ⌥ whilst pressing either the = key to zoom in or – key to zoom out), it was a feature I and I’m sure many others found useful; quickly zooming in to show something you’re looking at to a friend across the room being the most prominent use. Luckily re-enabling this feature is as easy as checking a checkbox, as I happily found out whilst delving through System Preferences trying to find the option to switch it back on.
Firstly, locate the Universal Access pane in System Preferences. As can be seen here, the Zoom options specify the shortcut keys for keyboard usage of this feature:
Before you go
After spending over 20 years working with Macs, both old and new, theres a tool I think would be useful to every Mac owner who is experiencing performance issues.
CleanMyMac is highest rated all-round cleaning app for the Mac, it can quickly diagnose and solve a whole plethora of common (but sometimes tedious to fix) issues at the click of a button. It also just happens to resolve many of the issues covered in the speed up section of this site, so Download CleanMyMac to get your Mac back up to speed today.