Questron was a battery-operated, interactive educational toy introduced in 1987 by Child's Play Ltd. Used in conjunction with special books, the reader could press the tip of the pen-like Questron to an answer to a question - with audible and visual guides showing whether the selected answer was right or wrong.
Technology
Questron used infra-red radiation to distinguish between different answer "areas". Two light-emitting diodes (one red, one green) would signify correct or incorrect answers and a small loudspeaker would add a sound effect to each answer. If both diodes activated, a small musical tune would be played to signify the "goal", or end of the lesson.
References
Questron (toy) Wikipedia(Text) CC BY-SA