Eye Accommodation: Use of Vernier Optometers in Behavioral Research

The history of the invention and development of devices suitable for the measurement of eye accommodation in behavioral research settings is briefly reviewed. A series of small experiments involving a Microvernier Optometer that is "worn" on the head demonstrated the practicality of using the device in a variety of dynamic, real-world situations including flying an airplane simulator, driving an automobile, and-with certain constraints-typing at a video display terminal. Some surprising incidental findings are relevant to virtual imaging displays and to the Mandelbaum effect.