Are this symptons related to a video card problem in Mac ?

Im having problems with my computer displays on my Mac...it seems the icons and fonts get distorted (thicker lines on some or some offseted lines running through them)even in my web brower... I check with a different monitor and still the same problem...I also logged in as a different user and the problem was fixed but when I'm in the Adm account the problem persist...Does anyone know what it might be?|||If it the problem doesn't show up in another account then it's the account that has problems and not the video card.