Direct students to a website full of optical illusions, such as Optical Illusions and Visual Phenomena (at michaelbach.de) or Mighty Optical Illusions (at moillusions.com). Have each of the students pick their favorite optical illusion. Students must be able to figure out how the optical illusion tricks the eye. After providing ample research time, have each student present her optical illusion to the class and see if the other students can guess how it works.
Provide a brief lecture on optical illusions and explain to students how some famous ones work. Divide the students into groups or allow them to work by themselves. Ask each of them to create an optical illusion. Suggestions for methods they can use include crayons, pens, paints and paper, graphic design programs on the computer or three-dimensional structures. Have each student or group of students present their optical illusion to the rest of the class.
If you have to fulfill certain writing requirements, have the students write a paper about optical illusions. Ask them to write a report about how optical illusions came into existence. One source to consult is the History of Optical Illusions website (at library.thinkquest.org). Another paper topic is to chronicle the life of a person famous for creating optical illusions. Give students creative freedom and have them write a piece of fiction that incorporates the concept of optical illusions.
Have students create an optical illusion that also acts as a piece of decor for the classroom or their home. For example, have them create a picture frame whose sides appear to be distorted (see visualillusion.net for ideas) or a series of painting samples with optical illusions on time.