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  Teaching Guide

Activity 1: Grades 5-8
Red-Eye Reducer

Image of eye

National Science Standards and Curriculum Links
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  1. Why was the inside of the eyeball model painted red?
    (The red represented the blood vessel-rich inner surface of the eye).
  2. What does the coin-sized opening represent?
    (The pupil)
  3. How did the angle of the incident flashlight beam affect the red-eye property of the model?
    (When the flashlight beam and observer's vantage were at the same angle, the red-eye effect was greatest. When the beam and viewer were at different angles, the inside of the eye that the observer could see was not illuminated and so appeared less red.)

Critical Analysis
Why does the angle of incident light affect the appearance of red-eye?
(If the light beam strikes the retina and reflects directly back at the camera, then the reflected light is red. If the beam is angled so that the reflected light doesn't travel back to the camera, then the region of the retina that the observer can see is not illuminated and therefore appears dark.)


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