The effect of prolonged light and dark adaptation on lens regeneration in the adult newt Triturus viridescens.

Light intensity has been shown to affect lens regeneration in adult newts. Experiments were designed to study the effects of different light controlled environments on lens regeneration in the newt T, viridescens. Animals were preadapted to three light conditions: control, light from below and dark for ninety (90) days prior to lentectomy. The newts remained in the controlled environments post-lentectomy to test the effects of light preadaptation on lens regeneration. The results indicate that controlled light sources from below cannot stimulate the ventral iris to regenerate a new lens or inhibit the dorsal iris from normal lens regeneration. Lens regeneration in preadapted dark animals is similar in rate and amount to the control group indicating a totally dark environment does not always inhibit lens regeneration.