css3で点滅させる

チカチカ点滅するものが見当たらなかったので下記リンクを参考に作ってみた。
CSS3: テキストをイルミネーションのように点滅させるアニメーション

.blink_class{
    -webkit-animation:blink 1.0s step-end infinite alternate;
    -moz-animation:blink 1.0s step-end infinite alternate;
    animation:blink 1.0s step-end infinite alternate;
}

/* 点滅 */
@-webkit-keyframes blink{
    21%,40%,61%,80%,100% {opacity:0;}
    0%,20%,41%,60%,81%,99% {opacity:1;}
}
@-moz-keyframes blink{
    21%,40%,61%,80%,100% {opacity:0;}
    0%,20%,41%,60%,81%,99% {opacity:1;}
}
@keyframes blink{
    21%,40%,61%,80%,100% {opacity:0;}
    0%,20%,41%,60%,81%,99% {opacity:1;}
}

もっとゆっくり

@-webkit-keyframes blink{
    34%,66%,100% {opacity:0;}
    0%,33%,67%,99% {opacity:1;}
}
@-moz-keyframes blink{
    34%,66%,100% {opacity:0;}
    0%,33%,67%,99% {opacity:1;}
}
@keyframes blink{
    34%,66%,100% {opacity:0;}
    0%,33%,67%,99% {opacity:1;}
}