Eagle, change component view
That is probably the keepout area of the device.

You can hide it by unselecting the respective layer.

Note that AFAIK only visible layers are tested during DRC. So if you want to test keepout compliance you have to make the layer visible again.

Another possibility is to rework the library. Apparently the keepout area was drawn as polygons. If you recompose it from rectangles the area will look a lot more cleaner. It may even affect CPU/GPU performance when rendering the picture.