Improved use of tapetal reflection for eye-position monitoring

A new technique is described for eye-position monitoring in species with strong tapetal reflections. A fiber optic is used to introduce light into the eye, whose optics then produce an image of the fundus on a tangent in front of the animal. The technique simplifies heretofore tedious measurement of cylotorsional changes, as well as providing a very wide view of the fundus. It has been used successfully in conjunction with single-unit recording from the visual system.