© 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Chapter 4Slide 1 LESSON...
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© 2011 South-Western | Cengage Learnin A Discovery Experience PSYCHOLOGY Chapter 4 Slide 1 LESSON 4.2 LESSON 4.2 Vision Vision OBJECTIVES Identify and illustrate the structures of the eye that are responsible for vision. Describe the way the brain perceives color.
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Chapter 4 © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Slide 3 Structures of the Human Eye The pupil is an opening in the iris that allows light to enter the eye. The iris is a ring of muscles that range in color from light blue to dark brown. The lens is a clear, elastic, disc-shaped structure that refocuses light. The retina is the light-sensitive surface at the back of the eye. The optic nerve carries information from the retina to the brain. The blind spot is the area on the retina where the optic nerve leaves the eye and that contains no receptor cells.
Transcript of © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Chapter 4Slide 1 LESSON...
© 2011 South-Western | Cengage LearningA Discovery ExperiencePSYCHOLOGY
Chapter 4 Slide 1
LESSON 4.2LESSON 4.2
VisionVision
OBJECTIVES Identify and illustrate the structures of the eye
that are responsible for vision.Describe the way the brain perceives color.
Chapter 4© 2011 South-Western | Cengage Learning
A Discovery ExperiencePSYCHOLOGY
Slide 2
Figure 4-1Figure 4-1
The Electromagnetic SpectrumThe Electromagnetic Spectrum
Chapter 4© 2011 South-Western | Cengage Learning
A Discovery ExperiencePSYCHOLOGY
Slide 3
Structures of the Human EyeStructures of the Human EyeThe pupil is an opening in the iris that allows light to
enter the eye.The iris is a ring of muscles that range in color from
light blue to dark brown.The lens is a clear, elastic, disc-shaped structure that
refocuses light.The retina is the light-sensitive surface at the back of
the eye.The optic nerve carries information from the retina to
the brain.The blind spot is the area on the retina where the
optic nerve leaves the eye and that contains no receptor cells.
Chapter 4© 2011 South-Western | Cengage Learning
A Discovery ExperiencePSYCHOLOGY
Slide 4
Figure 4-2Figure 4-2
Major Structures of the Human EyeMajor Structures of the Human Eye
Chapter 4© 2011 South-Western | Cengage Learning
A Discovery ExperiencePSYCHOLOGY
Receptor SitesReceptor SitesThe retina has two kinds of receptors that pick up
light. They are Rods and Cones-both named because of their shape.
There are 120 million rods per retina and 8 million cones per retina.
Rods-respond to varying degrees of light and dark. They are responsible for night vision.
Cones allow us to see colors as well as light and dark. Cones are less sensitive to light than rods are.
Cones are found mainly in the fovea, where no rods are found.
Slide 5
Chapter 4© 2011 South-Western | Cengage Learning
A Discovery ExperiencePSYCHOLOGY
Importance of VisionImportance of VisionVision is one of our most important
senses. 70% of our bodies receptors are located in our eyes
Slide 6
Chapter 4© 2011 South-Western | Cengage Learning
A Discovery ExperiencePSYCHOLOGY
Which person looks friendlier? Which person looks friendlier?
Slide 7
Chapter 4© 2011 South-Western | Cengage Learning
A Discovery ExperiencePSYCHOLOGY
Adjusting to LightAdjusting to LightWhen it is dark your rods become more
sensitive to light. This process is called dark adaptation. It takes about 20-30 minutes for all of your rods to adjust.
When going from dark to light it only takes a matter of a minute for you to adjust to the light and become less sensitive. This is called light adaptation.
Slide 8
Chapter 4© 2011 South-Western | Cengage Learning
A Discovery ExperiencePSYCHOLOGY
Slide 9
Color VisionColor VisionAll the colors you see are red, blue, and
green, or a mixture of these three.The color is in your visual system.An object appears as a particular color
because it absorbs or reflects certain wavelengths of light.
Colors are created by the cones in your eye responding to wavelengths and sending neural signals to your brain, which then creates the colors you see.
Chapter 4© 2011 South-Western | Cengage Learning
A Discovery ExperiencePSYCHOLOGY
Slide 10
Color BlindnessColor BlindnessColor blindness is a deficiency in the
ability to distinguish among colors.
