RE: Sclerotic rings

[Alan Watson <atw@hep.ph.bham.ac.uk>]

Gordon Martin Human wrote:

> Given that eyes are filled with fluid, and fluids are by nature
> incompressible, I don't see this as a valid hypotheses.

Fluids are incompressible, but fluid-filled sacks can be deformed, so it
isn't a priori crazy that a compensatory structure might be of use
in maintaining visual acuity (whether the pressure comes from depth, motion
or whatever). As for whales, are any of them primarily visual hunters? Animals
which use echo-location should have less stringent visual requirements, so
maybe they aren't really comparable anyway?

Alan