Eyebrows, in particular, "frame" the eyes and are a reference point that determines how facial features are perceived. The appropriate eyebrow shape and size can appear to lift a person’s eyes creating a more youthful appearance. Properly designed eyebrows can balance the distance between eyes or modify the look of prominent or deeply set eyes. A good eyebrow design can also make cheekbones appear more defined and influence the perception of the person’s nose size.
Here is a picture of a slight modification, before and after, of a client's eyebrows. The client wanted to stay extremely natural looking but have an "enhanced" eyebrow appearance.
Sovay Reeder, Aesthetic Boutique at Salon Sovay.