The recently increased interests in visual measurement and control applied to underwater robots have challenged the existing visual technologies that once were sufficient in ground-based applications. This paper surveys the major difficulties and representative applications in underwater visual measurement and control, most of which result from the particularity of the aquatic environments. Specifically, the state of the art of the underwater vision is summarized from different perspectives, primarily involving key points and existing problems. In particular, the application of the embedded vision-based system in the context of bionics is accented. Finally, the potential development trends and possible breakthroughs are discussed, shedding light on the effort both in hardware and software to advance real-world underwater vision applications.