Lightroom’s lens profiling function, like a number of pre-existing plug-in tools, provides lens distortion correction, chromatic aberration correction, and vignetting correction. Or in simple terms: it eliminates fisheye effects, color blurring, and darkening of the corners of your images. These effects are separate from autofocus calibration. All of them are desirable features, and they work together nicely. You can use them all in conjunction with one another to optimize your photos.