Strange 'Stretch Marks' after rendering Object in the viewport, Solid shading:



Object rendered:



Here you can see before and after rendering. There are some distortions and irregularities visible on the front face of the mesh between the circles which are supposed to be the eyes.
How can i fix/prevent this?
The geometry around the eyes is deformed and bad topology makes it obvious.

Select the outer edge ring around both the eyes.



Scale them to 0 along the Y axis (in your case). In my image it is the X axis. To do this, this: S Y  0  enter.