• placed covers on eyes and sharks were helpless
• eyes were very important
• sharks see in color - gruber

• small, well developed
• wide range of light intensity
• smallest eye- torpedo ray
• larget eye- big eyed thresher

shark eye

(cont)

• situated lateraly- pelagic
• situated dorsally- benthic
• oppose each other 360 degree view
• small binocular overlap- cannot see directly infront or behind
• eyes deep in head - streamline
• some have nictitating eye lids, other roll eyes back

• sclera- 3rd layer- determines eye shape
• chorid- middle layer- tapetum lucidium
• retina- inner layer- contains rods and cones
• rods = light; cones = color

• silver guanine crystals
• melanin granuales cover in bright light
• reflect light in dark
• twice as effective as cats

• number of R & C varies depending on shark ecology
• diurnal- R:C, 6:1
• dimlight- 100:1
• skates: photoreceptor acts like rods and cones
• dim light= rod, bright light= cones

• sharks thought to be far sighted
• pennial eye- third eye on top of head
• detects light: helps with vertical migration, deep sea sharks
• white sharks spy hop- stick head out of water to look around
• mechanism to see in air and water

• no true pupil area
• iris forms operculum with scalloped edge and aids in light regulation into eye