This study is about the development of a Model Apparatus for the Lecture-Demonstration of the Human Eye. The aim is to design and construct an apparatus that mimics the optical principles of
human eye in carrying out the processes of accommodation, the common vision defects and their corrections using appropriate lenses. The study comprises three areas: I.) design and improvisation II.) materials selection III.) construction and testing.
The Model Apparatus of the Human Eye produced in this effort include an improvised lens made of an IV (intravenous) bag filled with water that could change thickness thereby altering its focal length. A hypodermic syringe acts as the improvised ciliary muscles. The image formed by the improvised lens can be seen on the “retina” located at the back of an improvised eyeball made of an aluminum succo. The improvised eyeball also has the ability to change diameter to show the two common defects of vision.
The demonstration apparatus made use of simple and easily available materials so as to work on a low budget. The apparatus will allow students to have a clear visualization of the optical principles involved and make the teachers’ presentation more meaningful.
From the trials performed, the apparatus is also able to show the processes of near and far vision. It is also able to carry out the two common vision defects of myopia and hyperopia and their corrections. However, the apparatus is limited in its display of the image, thus the apparatus could be used only for a small audience.