Unit 5b Special Senses

EYE & VISION

If you want to preview the eye dissection here is a great link- it's good to review for the eye quiz on Friday

http://www.exploratorium.edu/learning_studio/cow_eye/

Also here is a video of a cow eye dissection: https://www.youtube.com/watch?v=6mNs_TcUyHc

Email me your answers for 1-12 below and I will tell you if you are correct! Margaret.mrosla@bellinghamschools.org

(Ignore the bottom 6’s, and 7 is a repeat of 4 as far as I can tell. 12 looks dark but it should be clear-maybe a shadow.)

Learning Objectives for Vision

• • Describe the type of lenses (concave or convex) that help focus light on the retina and be able to describe how to correct nearsighted and farsighted vision

  • Describe each of these eye disorder in terms of cause and symptoms: glaucoma, red/green colorblindness, astigmatism, diabetic retinopathy, macular degeneration, cataracts.

  • Describe each of the following stuctures in the eye and their functions.

• • • • Video Links:

      • Bozeman Science - Special Senses - I highly recommend this one!

      • https://www.youtube.com/watch?v=TAzTFgPSPiU

      • Vitamin A Detectives from Rx for Survival - Back to the Basics:

      • http://www.pbs.org/wgbh/rxforsurvival/series/champions/alfred_sommer.html

      • Red/Green Colorblind Primates: (SHOWN IN CLASS!)

      • https://www.youtube.com/watch?v=8bZXM0p5JFQ

• • ANSWERS FROM ABOVE: Email me your answers and I will email you mine!

    • EYE & VISION

    • If you want to preview the eye dissection here is a great link- it's good to review for the eye quiz on Friday

    • http://www.exploratorium.edu/learning_studio/cow_eye/

    • Which of these lenses is most like the eye? What is it doing to light? Notice how the inside is brighter on the top and the edges cast a shadow. On the bottom the inside is not as bright but it creates a hallow instead of a shadowed edge.

• • • If you answered the bottom one that was a decent guess because it was the only other option. If you answered the top one, you are correct! That lens is 'converging' the light rather than 'diverging' (or spreading) the light. What other structure in your eye also does this? Yes, the cornea! (The light shining through the aqueous and vitreous humor play a small role, too, just because of their different densities.)

Video Links:

Bozeman Science - Special Senses - I highly recommend this one!

https://www.youtube.com/watch?v=TAzTFgPSPiU

Vitamin A Detectives from Rx for Survival - Back to the Basics:

http://www.pbs.org/wgbh/rxforsurvival/series/champions/alfred_sommer.html

Red/Green Colorblind Primates: (SHOWN IN CLASS!)

https://www.youtube.com/watch?v=8bZXM0p5JFQ

What does it mean to be nearsighted/farsighted? What causes this and how can you correct it? (Can you answer those questions now?)

Image above: The optic disk - a.k.a. blindspot

Image above left: Emery and Rachel SeeAnatomyEverywhere - here they re-learn about night vision at the Tiger exhibit.

Image above right: Detaching the retina and revealing the tapetum lucidum on the cow's choroid layer. This pretty feature of the cow's eye allows for better night vision by scattering light.