docs: def eye(ax, p0, size=1.0, alpha=0, format=None, **kwds):
      r"""Draw an eye."""
      if format is None: format = 'k-'
  
      N = 100
      ang0 = pi-3*pi/16; angf = pi+3*pi/16
      angstep = (angf-ang0)/(N-1)
      x1 = [size*(cos(i*angstep+ang0)+1) for i in range(N)]
      y1 = [size*sin(i*angstep+ang0) for i in range(N)]
  
      ang2 = ang0+pi/16
      x2 = [size, size*(1.2*cos(ang2)+1)]
      y2 = [0, 1.2*size*(sin(ang2))]
      y3 = [0, -1.2*size*(sin(ang2))]
  
      N = 100
      ang0 = ang2; angf = ang2+4*pi/16
      angstep = (angf-ang0)/(N-1)
      x4 = [size*(0.85*cos(i*angstep+ang0)+1) for i in range(N)]
      y4 = [size*0.85*sin(i*angstep+ang0) for i in range(N)]
  
      cur_list = [(x1, y1), (x2, y2), (x2, y3), (x4, y4)]
      cur_list = rotate_and_traslate(cur_list, alpha, p0)
  
      for curi in cur_list: ax.plot(curi[0], curi[1], format, **kwds)