<defs>

      <filter id="blurFilter" y="-5" height="40"

          <feGaussianBlur in="SourceGraphic" stdDeviation="3" y="-"/>

      </filter>

  </defs>

  <ellipse cx="55" cy="60" rx="25" ry="15"

           style="stroke: none; fill: #0000ff; " />

​

  <ellipse cx="155" cy="60" rx="25" ry="15"

           style="stroke:none; fill:#0000ff; filter:url(#blurFilter);" />

</svg>