Eye candy is something that's nice to look at but doesn't make you think very hard or have any real importance. Many fashion magazines are full of pictures that are nothing but eye candy.
If a movie is full of attractive actors lounging on lovely beaches and laughing in the sunshine but doesn't offer any message or important theme or lasting images, you might describe it as being just eye candy. The earliest use of eye candy experts can find is a 1978 review of the TV show "Three's Company," which criticized it as having no lasting value despite being pretty to look at — just eye candy.