Figure 20.20: These plastic beads reflect light of different wavelengths, so they appear to be
different colors. ( 3 )
vision problems are myopia and hyperopia. To watch an animation that shows how these
two vision problems occur and how they can be corrected, go tohttp://pennhealth.com/
health_info/animationplayer/seeing.html.
Myopia
Myopiais also called nearsightedness. It affects about one third of people. People with
myopia can see nearby objects clearly, but distant objects appear blurry. How a person with
myopia might see two boys that are a few meters away is shown inFigure20.21.
Figure 20.21: This is how a person with normal vision sees the two boys(Left)Normal Vision
(Right)Myopia. ( 8 )