Search for similar images on Google Images, TinEye, Яндекс.Картинки, Baidu, KarmaDecay, IQDB, Saucenao, Imgops.
In order to make it work in Google Images, you need to install this extension: https://addons.opera.com/ru/extensions/details/fix-google-image-search/?display=en
PS extension will no longer be updated. I hate the new Opera, just as I loved the old one.
- This extension will access your tabs and browsing activity.