Greasemonkey script for darkening your web browser

sunglasses.js

// ==UserScript==
// @name     Webkit's filter may globally dim
// @description web pages in a pleasing manner
// @grant    GM_addStyle
// @run-at   document-end
// @exclude *://*.github.com/*
// @exclude *://github.com/*
// ==/UserScript==

function addStyle(css) {
  var head = document.getElementsByTagName("head")[0]
  if (!head) return
  var style = document.createElement("style")
  style.innerHTML = css
  head.appendChild(style)
}

addStyle(
  "html { filter: brightness(70%); -webkit-filter: brightness(70%); -moz-filter: brightness(70%); }"
)