Vision of Fish By Andrew McDonald.
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Vision of Fish By Andrew McDonald www.yahoo.com
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Outline Introduction Challenges of water Absorption of light Refraction of light Anatomy of eye Light regulation Jim Lavarakas
Transcript of Vision of Fish By Andrew McDonald.
Outline
• Introduction• Challenges of water• Absorption of light• Refraction of light• Anatomy of eye• Light regulation
Jim Lavarakas
IntroductionOptics : the collection of light and formation of an
image by the lens
www.haroldcheck.com
Accommodation : focusing of images on the retina
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Eyes of Fish• Much like
human eyes• But no eye lids• Many sizes and
colors
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www.ebiomedia.com
Anatomy of Eye• Sclera• Cornea• Lens• Iris• Retina• Optic nerve
Powerful Eyes• Spherical lens
• High refractive power
• High quality
• Receptors: cones and rods
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www.appstate.edu
Problems With Seeing Problems With Seeing Under WaterUnder Water
• Suspended particles
• Light absorption
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•Light refraction
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Suspended Particles
• Sediments• Microorganisms• Plant growth• Fast-moving
waterwww.hurleywi.com/ what_to_do/default.asp
Light Absorption
• The dimming of light as it passes through water
• Red wavelengths absorbed rapidly
• Blue wavelengths absorbed slowly
• Deep ocean is blue
www.google.com
www.rainbows.com
Light Refraction• Cone of Vision
• Water bends 48.6 degrees
• Freshwater pools
• Snell’s window
Snell’s window
Light Regulation
• To limit light• Iris contraction• Smaller eyes• Migration of visual
cells• Cornea filter
pigments• Swim away from
light
Light Regulation• For more light:
• Mirrors in back of eye
• Larger eyes• Swim toward light
www.google.com
Walleye
Conclusion
• Some similarities w/ humans
• Different environments
• More obstacles• More diverse• Altered behaviors
