characteristic -

due to -

resulting in -

(references)

reduced light

light is attenuated exponentially with depth so that no usable surface light remains at a depth of 1000 m.

Eyes are adapted for increased sensitivity, leading to light-induced damage.

Reduced temporal and spatial resolution.

Changes in the eyeshine leading to maximum sensitivity with minimum visibility to predators.

Shelton, Gaten & Chapman (1985; 1986); 
Chapman, Shelton, Shanks & Gaten (1989; 2000);  Gaten (1988); 
Gaten, Shelton, Chapman & Shanks  (1990);  
Gaten, Herring & Shelton (1999); 
Herring, Gaten & Shelton (1999)

Gaten & Shelton (1993)
Shelton & Gaten (1996)
Johnson, Shelton & Gaten (2000) 

Shelton, Gaten & Herring (1992)
Shelton, Gaten & Johnson (2000)
Johnson, Shelton, Gaten & Herring (2000)

vertically polarized light field

the light comes mainly from above, with the downwelling irradiance up to 1000 times the upwelling irradiance.

Gradients of morphology within the eye.

Gaten, Herring & Shelton (2002)
Gaten, Shelton & Herring (1992)
Gaten, Shelton & Nowel (2003)

monochromatic, low contrast background

the selective absorption of long and short wavelength light results in an increasingly monochromatic background light with reduced contrast due to the scattering of light.

Changes in spectral sensitivity.

Contrast enhancement through rhabdom modification.

Johnson, Gaten & Shelton (2002)
Gaten, Shelton & Herring (1992)
Gaten, Shelton & Nowel (2003,2004)

ALL OF THE ABOVE

Modifications to the structure and optics of the eye. Changes in eye development and evolution.

Gaten, Shelton & Herring (1992)
Gaten (1990, 1994) Gaten & Herring (1995)
Gaten, Herring, Shelton & Johnson (1998a, b)
Gaten (1998) Gaten (2007)