Anatomy of Eye

Introduction
How did eyes evolve? How did retinas, their receptors, lenses, irises, controlling muscles develop? Eyes have gone pretty far way in evolving till becoming as sophisticated as it is now. It’s challenge to the Charles Darwin theory of evolution by natural selection.
Main part
Every living thing is sensitive to light. Plants also use light. The first eyes respond only on light and it’s changing – this sensitive spots was all over body. Then were other cells all over skin which have receptors sensitive to movements.
Photoreceptors concentrate in one point like in a pit and have ability recognize shadows movements. Than developed transparent membrane over primitive glass and there was no lens – just pinhole to form image. Than membrane become thicker it …