Devices 2x images
<link rel="stylesheet" href="1x.css" media="only screen and (-webkit-device-pixel-ratio: 1)" />
<link rel="stylesheet" href="2x.css" media="only screen and (-webkit-device-pixel-ratio: 2)" />
OR
@media only screen and (-webkit-device-pixel-ratio: 1){
.image{ ... }
}
@media only screen and (-webkit-device-pixel-ratio: 2){
.image{ ... }
}