macOS Sierra: Magnify the mouse pointer
If you have difficulty seeing or following the mouse pointer when it moves—or changes to an insertion point, crosshair, or other shape—you can increase its size.
Choose Apple menu > System Preferences, then click Accessibility.
Click Display, then drag the Cursor Size slider to the right to make it larger.
Tip: To make the pointer larger temporarily, quickly move your finger on the trackpad or quickly move the mouse. To turn this feature off, deselect “Shake mouse pointer to locate” in the Display pane of Accessibility preferences.