Is there a mac utility that can magnify parts of the screen?

Go to System Preferences, then Accessibility. There will be a column on the left for Zoom, which you can use a keyboard shortcut to activate.

Once activated, hitting ⌥-⌘-+ will zoom the screen.

You don't say which version of osx you are using, in 10.8.2 go to system preferences, accessibility, zoom, then under zoom style select picture-in-picture. The zoom box will follow your cursor. Older versions had this option not sure of the steps for other versions.

Try the following apps:

• Zoom It

• Virtual Magnifying Glass

There are at least one other, but Zoom It app is the one that most reviews recommend. I use it with a 40 inch 4k display. Awesome!