210 likes | 619 Views
The Eye. How Vision Works. Light. Sight works by detecting light. No light = black Lots of light = white. Light è Eye. Light rays reflect off objects and enter your eye. Ex. Looking at a book. Or light enters your eye directly. Ex. Looking at the sun. How Vision Works.
E N D
The Eye How Vision Works
Light • Sight works by detecting light. • No light = black • Lots of light = white
Light è Eye • Light rays reflect off objects and enter your eye. • Ex. Looking at a book. • Or light enters your eye directly. • Ex. Looking at the sun.
How Vision Works Image you see inside your eye is upside down. Brain Pop Video- Vision Problems http://www.brainpop.com/search/search.weml
Eye • The eye is an organ that has many parts. • Each part aids in vision.
Cornea • Clear, dome-shaped surface that covers the front of the eye. • 2 Jobs • Acts like a shield. • Helps focus light.
Iris • Colored part of the eye that determines how much light enters the eye. • It’s a muscle
Pupil • Opening in the center of the iris • Black part of eye. • Bigger pupil lets in more light. • Smaller pupil lets in less light.
Lens • The lens changes shape to focus the image. • It’s flexible
Retina • Back of your eye, where images form. • There are light sensitive cells called photoreceptors. • Cone Cells (Color- red, green and blue) • Rod Cells (Black and White) • Convert light into electrical signals
Optic Nerve • Sends the signal to the brain.
Brain • Brain interprets image.
Fact- Average Human Eye • Contains • 130 million rod cells • 7 million cone cells • Your brain evaluates all 137 million cells about 15 times and each second.
Summary • Brain Pop Video- Eyes • http://www.brainpop.com/search/search.weml
Lets go to page # 69 • -Label • -Color • -describe functions Use Life Science textbook p.330 and Classnotes: Eyes
Lab- Eye Dissections • Follow all directions • Read instructions step by step • http://www.exploratorium.edu/learning_studio/cow_eye/coweye.pdf • Take out each structureand label it. • And take a picture of each structure with your iPad • Draw each structure on the lab worksheet provided
Anatomy of the Eye • Please go online to read about the sheep eye dissection. • Test your self. http://science.jburroughs.org/resources/skeleton/eye/eyetitle.html
Clean Up Time • Put all the eye parts on the trash can. • And rinse tray and scissors.