Powerful, complex and fragile, the eye is the organ the most solicited from our five senses. Because vision is vital for learning, working and everyday living, we need to correct and protect it as well as prevent any visual defects or diseases. Iris, lens, cornea, retina, pupil… Understanding the functioning of the eye is critical for adopting good habits and preserving visual health. Since the first pinhole spectacles to progressive and photochromic lenses, ophthalmic optics has been a major focus of great innovations. Innovations which Essilor has contributed to.