What it is: The Eye Definer Brush does double duty, softly lining eyes and filling in and strengthening thin or sparse brows.Who it's for: It's ideal for those who prefer to use a powder eyeshadow as an eyeliner and for anyone who wants to create a natural-looking brow.Why it's different: Its soft but sturdy bristles deliver just the right amount of shadow to the lash line or brows.How to use: If using as an eyeliner, apply the eyeshadow as close to the lash line as possible for a beautifully defined eye. To fill in brows, start at the inside corner of the brow and brush upward and outward in quick, short strokes following the natural arch of your brow.

• By Bobbi Brown.