效果图：
素材：
close.png
open.png
源码：
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>无标题文档</title>
<style>
.box {
position: relative;
400px;
border: 1px solid #E3E3E3;
margin: 100px auto;
padding: 2px;
}
.box input {
370px;
height: 30px;
border: 0;
outline:none;
}
.box img {
position: absolute;
top: 4px;
right: 6px;
24px;
cursor: pointer;
}
</style>
</head>
<body>
<div class="box">
<label for="">
<img src="images/close.png" alt="" id="eye">
</label>
<input type="password" name="" id="pwd">
</div>
<script>
var eye = document.getElementById('eye');
var pwd = document.getElementById('pwd');
var flag = 0;
eye.onclick = function () {
if (flag == 0) {
pwd.type = 'text';
eye.src = 'images/open.png';
flag = 1;
} else {
pwd.type = 'password';
eye.src = 'images/close.png';
flag = 0;
}
};
</script>
</body>
</html>