[Theme: Headway] Change opacity w/ hover of side-widget images

Hello there,

Here is a link to my webpage, firstly. https://houseofmuses.net

I’m trying to get the images in my sidebar widget areas to drop down to .8 opacity when moused over. The widget is a SiteOrigin Editor widget, with image added. I’m specifically looking for only the images which are links, so the ones that link to posts, to my shop, etc.

I can’t seem to figure out how to do it.

Thanks! ??