Re: Are seals color blind?

hi Kristen!!!

I believe that seals are not color blind since they have excellent vision. 
They can even see in dark and distinguish.

Basic mechanism-

Seals belong to sub-order Pinnipedia of Class Mammalia.
Seals spend much of their time above water. An oily secretion keeps the 
surface of the eye lubricated. Since there is no lachrymal duct, the seal 
eye "weeps" profusly all the time.  The seal cornea does not bend light 
rays like that of land mammal; the cornea, aqueous humur and vitrious 
humur all have the same refractive index as water.  The pupil in seals is 
capable of great expansion to facilitate vision at moderate depths.  The 
cornea is astigmatic, but for vision in air the natural long sightedness 
of the system is compensated for by the reduction of pupil to a narrow 
vertical slit.  This counteracts astigmatism of the cornea and permits 
reasonably sharp focus and also facilitates them to see in dark.

You can get more information at these sites;
1. www.aqua.org/animals/species/seals.html
2. www.press.jhu.edu/books/walker/pinnipedia.html

shashank Harithsa
Mad Scientist
July 16,2001