Lazy loading and SEO

[mikeg2010]

In order to lazy load the images I have to use the data-src attribute and leave the src attribute out of the img tag. I tried using both but the browser doesn't lazy load the images, it loads them right away. And when I remove the src attribute it fails the W3C validation, which according to various SEO sources is not good for search ranking. Leaving src ="" works with lazy loading but it still fails W3C validation. Another suggestion was to use a transparent inline image like data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw== but the slider simply returns a blank screen.

Is there a workaround that will lazy load the image and be SEO-friendly?