Blender how to round edges of face

Question

I'm trying to make a round eye in my object by selecting a face, pressing e, dragging it into the face a little bit and I'm trying to make that eye round instead of square. How can I do this?

Solution

There is "To Sphere" AltShiftS available under Mesh->Transform. As the name suggests it adds a spherical influence, if the selected verts lay flat on a plane the result is circular.

Another option is an addon called LoopTools. Enable it and you have some extra options in the specials menu (W) which includes Circle, which will give a circular influence to the selected vertices.