[anthk]

In my case, gopher://gopherddit.com under Lynx. As for the config -file:

     cp /etc/lynx.cfg $HOME/.lynx.cfg 
    export LYNX_CFG=$HOME/.lynx.cfg

At lynx.cfg:

VIEWER:application/postscript:fbgs %s VIEWER:image/gif:sxiv -a %s VIEWER:image/x-xbm:sxiv -a %s VIEWER:image/png:sxiv -a %s VIEWER:image/tiff:sxiv -a %s VIEWER:image/jpeg:sxiv -a %s VIEWER:video/mpeg:mpv %s VIEWER:video/mp4:mpv %s

Install sxiv and mpv, of course.