White lines along bottom of MacBook Air screen

Along the bottom 1/4" of my screen I have multiple white/grey horizontal lines that run across the entire length of the screen. This occurs at startup and remains the entire time the computer is in use. Rest of the computer screen looks great this only appears along the bottom 1/4" of screen and is visibile any time the computer screen is in use. MacBook Air was purchased new as a Christmas present so it is less than 6 months old and the lines first started becoming visible a couple months ago.