Epidiascope is a projector capable of projecting images that are both transparent and opaque. Epidiascopes are projectors with an episcope and a diascope combined into their optical system. The epi-position allows it to project opaque, flat objects, like books. Using an appropriate slide carrier, slides can be projected in the dia-position. Brighter bulbs were used to project these opaque objects in an epidiascope. For the majority of the 20th century, the epidiascope became very helpful in educational settings.
It was used as a tool for teaching. Books, journals, charts, etc were projected directly on the screen with the help of Epidiascope. It was an effective tool to teach a large group of students. As new advanced inventions came into being, the epidiascope was replaced by new tools. A variety of tools were invented following the invention of the epidiascope. Teachers shifted from one tool to another as the technology advanced to facilitate the pedagogical process.
Today, there are many options available to teachers. For them to have an impact on their students, there are several instructional instruments available at their fingertips. Teachers instruct their students using videos, simulations, 3D models, augmented reality, etc. The efficiency of teaching has improved along with the development of teaching technologies. Unlike before, students find the learning process fun and enjoyable. Teachers use a variety of tools to make their students engaged in the learning process. With the help of technology, the learning retention rate of the students has increased and they are bringing about a number of changes in society with the knowledge they are acquiring.