Subject: Eye Sight in Whales

Kim Marshall (kimm@oceanalliance.org)
Thu, 21 Oct 1999 08:56:22 -0400

Reply:
Dear Simon:
It is believed that whales, at least toothed whales including dolphins,
have similar eyesight to humans.  Underwater, whales can only see about 35
feet when there is light but they rely on sound (SONAR) to see in the dark.
Dolphins regularly chase fast prey and probably rely on close-vision sight
for hunting but the larger baleen whales that eat plankton and probably use
other senses to find their prey.  When humans try to see underwater we
become farsighted - whales have adapted to this by having a globular lens
which acts like the convex lenses we need to correct our vision underwater.
It is believed that toothed whales are shortsighted in air and can see
about 30 feet.  Since whales lack smell and other chemical senses they have
compensated by developing good eyesight and very technical hearing.  Their
eyes can withstand great pressure and secrete an oily substance that
protects their eyes from the effects of salt. I hope this information helps
you, please search WhaleNet's pages for more information.

Question:
 Hi Kim, I believe whales have very good eye  sight. Is this correct?And if
so, why?   Do species differ in this respect.

Kim Marshall-Tilas
Whale Conservation Institute/Ocean Alliance
191 Weston Road
Lincoln, MA  01773
(781) 259-0423
fax: 259-0288
website: http://www.oceanalliance.org