A 4K resolution on a 13.5-inch monitor? That's almost as bad of a waste of GPU as mining bitcoin.
Just for fun I did some calculations, at 1080p a pixel is 0.1483 mm wide, at 4K it's 0.0742 mm. With the eye's angular resolution of 1 arcminute at say half a meter away, that's 500 mm * tan(1/60°) = 0.1455 mm. Even someone with perfect eyesight could hardly be able to tell. Do you intend to use it as a VR headset?