Believing Is Seeing

1. To do a study of blind spots.     
2. To create a demonstration that illustrates and explains blind spots in human perception.     

Research Questions:     

• What is a blind spot?     
• What causes a blind spot?     
• How is a blind spot identified?     
• Why do we not normally perceive blind spots?    

A blind spot is an absence of sight in a particular area of one's field of vision. Human blind spots are caused by interference from the optic nerve in the place where it connects to the retina. Experts say that visual information located in the blind spot is supplied by the other eye. But if this is true, then why don't we see the blind spot when we close one eye? In this project you study blind spots, run experiments in blind spot detection, and create an original blind spot demonstration of your own.

Materials:

• Computer with Internet access     
• Color printer     
• Digital camera     
• Typical office/hobby/hardware/craft supplies (paper, poster board, glue, etc.).     
• All necessary materials can be found in or around your home, at local stores, or on ebay.

Experimental Procedure:     

1. Read overview of relevant topics (see bibliography below and terms listed above)     
2. Address all of the above terms and research questions.     
3. Search and print out interesting images relevant to your topic.     
4. Take photographs throughout the course of the experiment.     
5. Take a look at some existing blind-spot experiments.     
6. Design an original blind spot experiment of your own, using the same principles used in previous blind spot experiments.
7. Test your design on a number of volunteers.     
8. Analyze your data.     
9. Interpret your findings in a detailed report.     
10. Include photos, diagrams, models and demonstrations in your science fair display.  

Terms/Concepts: Optic disc; Optic nerve; Photoreceptor cells; Scotoma

References: 

• http://en.wikipedia.org/wiki/Blind_spot_%28vision%29 (Blind Spot – an overview)     
• http://serendip.brynmawr.edu/bb/blindspot1.html (A comprehensive discussion of blind spots).     
• http://www.formulamedical.com/Topics/Head&Neck/blind%20spots.htm (More about blind spots).     
• http://www.hometrainingtools.com/blind-spot-experiments/a/1252/ (Blind spot experiments).     
• http://faculty.cs.tamu.edu/choe/extra/filling-in/ (More blind spot experiments)     
• Internet searches of your choosing.  Search words or terms listed here, or make up your own phrases.  Click on any results you find interesting.  Have fun surfing the net!