Simple, inexpensive and versatile, this device can be used to gauge field of vision, reading field, and peripheral vision. Demonstrate natural variations in these capacities among students. Calibrated in degrees and with a moveable sight, this device can be used to illustrate the importance of these visual parameters to everyday activities. Opthalmologists rely on similar measurements to diagnose vision problems and as indicators for necessary treatment and care. Complete instructions and lesson ideas are included.