или так
<!DOCTYPE html>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<script>
document.addEventListener("DOMContentLoaded", function() {
let linza = document.querySelector("#linza");
let str = "1.0,1.5,2.0,2.5,3.0,3.5,4.0,4.5,5.0";
str = str.split(",").map(v => new Option(v, v));
linza.append(...str)
})
</script>
</head>
<body>
<select id="linza"></select>
</body>
</html>