The Physics and Biology of the Eye

Concept or conceptual understanding:

This activity follows the dissection of the eye where students were asked to speculate as to how the various structures work together to provide vision.  In this activity, students will explore the physics behind sight and the biology involved, including typical diseases of the eye.

Real world connections (Relevancy):

Many students are either near-sighted or far-sighted, but are unaware of what those terms actually imply.  They also have family members or friends who may have various diseases associated with the eye.  This activity will clear up misconceptions and address ways to care for their own eyes.

AZ standards: (Science Standards Articulated by Grade Level – High School)

S1C1PO 2.  Develop questions from observations that transition into testable hypotheses.

S1C3PO 2.  Evaluate whether investigational data support or do not support the proposed hypothesis.

S4C5PO 5.   Describe the levels of organization of living things from cells, through tissues, organs, organ systems, organisms, populations, and communities to ecosystems.

Incorporation of inquiry:

During the physics portion of this activity, students will use lab tools to experiment with focusing a light in a particular spot.  They will manipulate the conditions to demonstrate near and far sightedness.  They will observe what happens when a lens becomes cloudy and relate that to the condition of cataracts.

Behavior objectives:

Manipulate variables (focal length, lens thickness, etc.) to see their affects on a system

Record factual information on a note taking sheet

Discuss how their model from the previous activity varies from the current scientific model of an eye

Determine the factors which cause disease in the eye

Prior knowledge necessary:

Having done the pig eye dissection prior to this activity, students will be aware of what structures are found in the eye.  They will have speculated as to what the function of each structure is and this lesson will either affirm or challenge those assumptions.

Identify possible student preconceptions:

Because of the common terminology used, students often confuse near and far sightedness.  They are not aware of which part of the eye is the muscle.

Materials:

Optics kit including lenses of various thicknesses

Metric rulers

Note taking sheet – one per student

PowerPoint on Biology of the Eye

Safety:

If the lenses are glass, students should be advised as to the danger of breaking the lens and cutting themselves. No other safety measures are necessary.

Lesson Description:

The class will be split into two groups (assuming that there are two teachers teaching this lesson).  One group will first do the physics of the eye and then the biology of the eye, and the other group will start with the biology and then do the physics.  Each activity takes about 40 minutes.

In the physics lab, the students will use an optics kit to experiment with focal points and the effect of different thicknesses of lenses.  They will discover how near and far sighted ness occurs, as well as how procedures like lasik work through a discussion with the teacher. 

In the biology portion, students will use a guided note taking sheet (see attached) to take notes from a PowerPoint (see attached).  The notes will help facilitate a class discussion on the structures in the eye and potential problems associated with the eye.

Assessment:

Students will take notes which will be checked for completion.  On the following day they will take a quiz over the structures found in the eye.  The quiz will have a labeling section as well as matching section relating structure and function (see attached). During the physics part of the activity they will create drawings which illustrate how the eye focuses light.