[Nerd]

        float r_dsp = max( (abs(0.5-texCoords.x)*abs(0.5-texCoords.y))-0.025 , 0.0);
          color.r=tex2D(sceneSample, (texCoords+.03*r_dsp )).r;
          color.g=tex2D(sceneSample, (texCoords+.01*r_dsp )).g;
          color.b=tex2D(sceneSample, (texCoords-.03*r_dsp )).b;