Edible Eyeball

By Laura Hospitál on Nov 03, 2016

Many thanks to Kathi Garza and Cindy Bachofer, TSBVI Outreach,  for sharing this activity. 
 
This activity provides a tasty way to learn about the structures of the eye. It can be presented as an introduction to the eye or as an informal assessment of the students' knowledge.  The procedure that follows is the informal assessment.

Vocabulary

  • lens - located behind the pupil - this structure focuses light on the retina
  • vitreous humor - jelly-like substance that makes up most of the eyeball
  • sclera - the"white" of the eye - surrounds the eyeball and protects it
  • cornea - the bulge located at the front of the eye - helps to refract (bend) light as it enters the eye
  • retina - acts like a "screen" on which the image is formed - located at the back portion of the eye - contains "rods and cone" which convert light into nerve impulses which are sent to the brain through the optic nerve.
  • optic nerve - leaves the back portion of the eye(retina) and brings information to the brain
  • iris - the diaphragm which opens and closes to adjust the amount of light which enters the eye
  • pupil - the aperture (hole) which allows light to enter the eye

Preparation:

Prepare materials for each student or group in a tub or bin for easy access. 

Materials

  • Marshmallows - Giant Campfire Variety - 1 for each student or group
  • Twizzlers - 1 for each student or group
  • RIPS (candy) - 1 for each student or group
  • Gummy life saver - 1 for each student or group
  • Brown Reese's pieces - 1 for each student or group
  • Frosting - can be shared among groups

Procedure

  1. After instruction on the structures of the eye, students are challenged to use the materials given each group to "make" an edible eyeball.
  2. Tell students that the items (candy) they were given will represent the sclera, optic nerve, retina, iris, and pupil.
  3. Students should construct the model as they see fit.  Then instructor will discuss the models with the students.
    • The following is a likely choice for each of the tasty items:
      • Marshmallow - vitreous humor covered by the sclera
      • Twizzler - optic nerve
      • RIPS -  retina
      • Gummy life saver- iris
      • Brown Reese's piece - pupil
      • Frosting - Used to hold it all together
  1. Give students 20 - 30 minutes to complete this activity with minimal interference.
  2. After all groups are through, discuss the choices groups made and the structures of the eye that are represented.
  3. Closure: Students should enjoy the fruit of their labors as they eat their creations.

Variations

Students can be given this activity to complete after instruction in the structures of the eye as per this lesson plan or as part of instruction. In the latter case, the function of each structure should be discussed as the edible eye model is constructed.   

NGSS Standards:

PS4.B Electromagnetic Radiation
An object can be seen when light reflected from its surface enters the eyes (4-PS4-2)
 
LS1.A   Structure and Function
Plants and animals have both internal and external structures that serve various functions in growth, survival, behavior, and reproduction (4-LS1-1)
 
LS1.D Information Processing
Different sense receptors are specialized for particular kinds of information, which may then be processed by the animal's brain. Animals are able to use their perceptions and memories to guide their actions (4- LS1-2)
 
 
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