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The EYE.

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Presentation on theme: "The EYE."— Presentation transcript:

1 The EYE

2 Eye Evolution The very earliest "eyes", called eyespots, were simple patches of photoreceptor protein in unicellular (one-celled) animals. All modern eyes, varied (different) as they are, have their origins in a proto-eye believed to have evolved some 540 million years ago.

3 Eye Evolution Multicellular (more than one cell) eyespots evolved, physically similar to the receptor patches for taste and smell. These eyespots could only sense the brightness of available light : they could distinguish light and dark, but not the direction of the light source.

4 Eye Evolution

5 Eyes in various animals show adaptation to their requirements
Eyes in various animals show adaptation to their requirements. For example, birds of prey have much greater visual acuity than humans, and some can see ultraviolet light.

6 Eye Anatomy Comparisons
Shark Eye Reptile Eye

7 How we see

8 RETINA- Rods & Cones Rods help us see black and white. Cones help us detect color. Only work in bright light. There are three types of cones. GREEN, RED, BLUE

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10 Color blindness is a problem with the color-sensing granules (pigments) in certain nerve cells of the eyes, called cones. They are found in the retina, the light-sensitive layer of tissue that lines the back of the eye. If just one pigment is missing, you may have trouble telling the difference between red and green. This is the most common type of color blindness.

11 If a different pigment cone is missing, you may have trouble seeing blue-yellow colors.
People with blue-yellow color blindness usually have problems identifying reds and greens, too. The most severe form of color blindness is achromatopsia, rare condition. Cannot see any color, so they see everything in shades of gray. Most color blindness is due to a genetic problem.

12 Do NOT Talk at all !!!!! Write letter or # and anything you see in the circle.

13 Eye Shape Affects Vision
Which lens type fixes which?

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15 Blind Spots and Peripheral Vision

16 Quiz 2 1 4 3 6 5 7 8 9 10 11 Aqueous Humor Cornea Optic Nerve Iris
Choroid Optical Disc Lens Pupil Retina Macula or Fovea Sclera Ciliary Body & Muscle

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