The present study was carried out to investigate the histological and histochemical
changes in the retina on different developmental stages of Egyptian toad Bufo regularis. Our
experiment started when tadpoles begin to feed. The adapted embryos are divided into 3
large tanks of 200 embryos each, collections of samples started from feeding age every
three days. Both histological and histochemical results showed that the general architecture
of the retina organ is correlated with the state of development. Therefore, it displayed
different characteristic features depending on the investigated developmental stage
starting from the larval stage (feeding began, stage 44) and ending with the postmetamorphic
stage 66. Also, the present work aimed to study the chronic effects of UVA
on the retina structure of B. regularis during development and metamorphosis for the first
time