... Or the video card is set on a smaller bit rate or resolution. It may be that the video card in your laptop may have an update that might address this as well.
Since I didn't see that option tried, I thought I'd mention that first.
if the monitor looks fine on the desktop, but not when hooked up to the laptop, that may point to the problem.
Either my monitor has a defect or this model has a hard time drawing color gradients. Below is a link to a picture taken from my phone of my desktop, which is a tile image of a gray scale gradient. The second link is to picture of a screenshot of my desktop viewed from my laptop. It's easy to see the lines where it's failing to merge the colors to draw a smooth gradient. This issue also appears when playing games or watching videos as any gradient of color tends to have shade lines visible.