sheep and shark eye Flashcards
(18 cards)
what is the sclera
white of the eye, CT.
what is a cornea
clear at front of eye = cornea
what may reptiles, birds, or fish have in their sclera
scleral ossicles (scleral
bones)
rods
low light sensors
cones
color sensors
tapetum lucidum
present in noncturnal animals
ciliary body
smooth
muscle around interior of eyeball, controls
visual accommodation, is attached to lens
via suspensory ligaments
iris
thin
continuation across front of eyeball,
muscles change size of pupil
pupil
opening in iris
retina
photosensitive layer of rod,
cones, and other cells
Some animals have
an indented fovea where
light converges –
composed of only cones
Chondrichthians have only
rods
Why do vertebrates have a “blind spot”?
the optic nerve route before the retina, blocking some light and creating a blind spot where the fibers pass through the retina and out of the eye. In octopus eyes, the nerve fibers route behind the retina, and do not block light or disrupt the retina.
The Conjunctiva
an
epithelia layer that covers
sclera and inner surface of
eye lid.
When infected = pink eye
Overlapping fields of view allow for
depth perception
main visual
processor in fish, reptiles, and birds
optic tectum
important
for visual processing in mammals.
visual cortex
Large panoramic fields of view characterize
animals
susceptible to attack
