Optical Illusion Eye Tricks. This one will make you dizzy. Try focusing on just the center circle while moving your head.

Transcription

1 Optical Illusion Eye Tricks This one will make you dizzy. Try focusing on just the center circle while moving your head.

2 Photocopy from original for best quality. H A N D O U T The Visual System The properly, human and eye send is composed messages of many to the parts brain. that work together. They receive visual images, focus them To things: have vision, you must have three S(1) eyes, Brain (2) (3) light. a brain, and Sun o how does all this work? We start L Eyes Light with light. ight are looking rays bounce at. Let s off an say object the object you a dog. The light reflects off the dog s is L Sun image and comes back to your eye. ight part then of the enters eye, called through the the cornea. outer The cornea cornea helps is the clear eye like to focus. a window. To focus The means clear. to make things look sharp and = VISION Iris Light Pupil Cornea N ext, pupil the is the light dark rays round go through circle in an the opening middle called of the the colored pupil. part The your eye. The colored part is called the iris. The pupil is really a hole of in the iris. The iris controls how much light goes into your eye. Continued on next page

3 Senses Experiment: Are Two Eyes Better Than One? How two eyes give you more depth perception, which is the ability to judge how near or far objects are. Two pencils 1. Hold a pencil lengthwise (on its side) in each hand. 2. Now, with one eye closed, try to touch the erasers together. Did you miss? 3. Now, try it with both eyes open. Voila! Two eyes give you better depth perception.

4 Scramble H A N D O U T Scramble and Word Search Unscramble the parts of the eye listed below.hint: The location of each is shown on the diagram. 1. dyelie 2. siir 3. lpuip 4. onarce rsleca 6. nesl 7. aclamu 8. stivorue mhuro 9. ovafe 10. pocit verne 11. drohcio 12. tranie Photocopy from original for best quality. WORD SEARCH Can you find these hidden words? IRIS EYE RETINA LENS CORNEA MACULA PUPIL CELL NERVE R A C L I N E R V E E E Y E Y T E A O Y R E T N E A C A C C P U P I L U E C L O N E S R N Y N O E R A P I I V A R T N N E I E S P A N Y S E M E I V A N I T E A E A S U O E R T I V T E C R A C U L A P O D D U T I E S D A F L E N L L D L N S D O R V E A M A L E Eye-Opening Facts History Us Tells Abraham was farsighted Lincoln had a lazy eye. and first pair of eyeglasses His 38 cents. cost about

5 Optical Illusion Eye Tricks Try to count the number of black dots on the image below

6 HANDOUT:The Visual System (continued) When iris closes the light the is pupil bright, until the right amount of light gets in. When the the pupil light to let is dim, in more the light. iris opens All of the happens automatically. You do not this Yhave to tell your eye do it! our rays eye of light. has a The lensto lens focus of the the eye through is behind the lens the on iris. its Light way to passes back of the eye. the The important. back of Lining the eye the is very eye is the retina. The inside retina of the includes sensitive 130 cells million that send tiny messages light- together other cells. at the These back cells of the come form the optic nerve. The eye optic to nerve is part of the brain. Fortunately decides how for you you, see. your The retina brain Wsees the brain the world turns upside it right down, side up. but hen each you eye look sees at a slightly an object, different combines picture. the images, The or brain that each eye sees and makes pictures, into one picture. them Pupil in Bright Light Lens Sun Pupil in Dim Light Optic Nerve Retina Photocopy from original for best quality.

7 H A N D O U T The Anatomy of the Eye Choroid(KOR-oyd) Eyelid A layer of blood vessels that The skin-covered structure The Iris feeds the retina. that protects the front of the regulates colored the part amount of the of eye; limits light entering the entering the eye. light The Cornea(KOR-nee-uh) clear outer part of the eye; spreads tears over cornea. eye s focusing system located Lens at the front of the eye. The Fovea(FOH-vee-uh) center of the macula; gives behind The clear the part iris of that the helps eye the sharpest vision. focus light on the retina. to Allows both far the and eye near to focus objects. on The Macula(MAK-yoo-luh) retina small sensitive area of vision; that contains gives the central fovea. The Optic nerve nerve bundle of over one million visual fibers that carries retina messages to the brain. from the The Pupil the opening at the center of size iris. The iris adjusts the the of the pupil and controls enter amount the eye. of light that can The Retina(RET-in-nuh) lining light-sensitive tissue sends the back of the eyeball; the brain. electrical impulses to The Sclera(SKLEH-ruh) tough, white outer coat of 12 the eye. (VIT-ree-us) Vitreous Humor The of the clear eye. gel filling the inside Photocopy from original for best quality.