It’s easy to take things for granted in this day and age, without stopping to think about the effort that went into creating the indispensable objects we use in our daily routine. Case in point: the contact lens. A product that today appears ordinary has reached us after a long journey made up of studies, ideas, intuitions and innovation.
The revolution of Leonardo Da Vinci
Many do not know that if today our eyes can enjoy the comfort and advantages
of fortnightly lenses, monthly, quarterly or daily, it’s because of Leonardo Da Vinci. The Renaissance genius, famous for his fundamental contribution to the most diverse fields of
knowledge, was a painter of unquestionable talent but also a scientist, capable of investigating human anatomy in an illuminating way. And to the study of the eye, and of the visual system, Leonardo devoted years of work to demonstrate how the visual function of the eye is determined by the crystalline lens and not by the retina.
Around 1508, Da Vinci developed a study that led him to elaborate the theoretical concept of a corneal lens. This historical document has survived the test of time thanks to its innumerable designs, among which there is that of a human face immersed in a container full of water. The famous drawing is accompanied by an annotation in which the painter explains the refractive power that water exerts on the human eye.
According to his studies, in fact, thanks to the water placed between the eye and the
surface of the container, the eye can see differently. Despite Da Vinci’s brilliant
intuitions, the invention of contact lenses remained a mere theoretical argument for many centuries, due to the absence of materials and technologies that allow effective production.
Descartes lends Da Vinci a hand
In 1636, Descartes joined in on the study of vision by writing the Diottrica, a thesis that deals with the subject from a theoretical, physical and physiological point of view. In addition to revealing the correct location of the optic nerve, thanks to a drawing that illustrates its position in the cranial conformation, Descartes added to Da Vinci’s studies, to the point of demonstrating
the possibility of reducing the visual defects of the viewer.
According to his theory, it is enough to simply place a concave glass lens on the hole of
a tube filled with water, and then place it on the cornea. Even then, we are still in a phase of theorization and rough experimentation, which will see the arrest of research for almost two hundred years.
The nineteenth century and the first practical applications
The leap that allowed us to go from Da Vinci’s brilliant theorem to the concrete ancestors of today’s contact lenses is thanks to Adolf Gaston Eugene Fick, Eugene Kalt and August Muller: the three ophthalmologists who in the nineteenth century gave life to the first official contact lens prototype. This concept started from the idea of the British astronomer Sir John Erschel, creator of the first lens mold. In 1887, Fick was the first to make lenses with corrective power. They were large and made of bulky brown glass, so one could only wear them for a couple of hours at most. Initially, the scientist experimented on a rabbit, before trying them himself, applying them on the cornea of his eyes. Kalt, on the other hand, tested them on several of his patients.
Muller was the first to coin the official name of “contact lenses”, used in his doctoral thesis, but also discovered that the production of the first glass lenses can correct nearsightedness.
The big breakthrough
In 1936, the American optometrist William Feinbloom had a true ‘eureka’ moment, thanks
to the introduction of plastic. Using plastic resulted in lighter, easier-to-use contact lenses that were ready to reach mass-production and distribution, though there was still a long way to go before designing the contact lens products we can find at top retailers today.
A few years later, the Los Angeles optician Kevin Tuohy created a version made of a special material: polymethylmethacrylate, a softer plastic substance that allows the
production of smaller and more comfortable lenses. Despite these advances, however, the
period between the 1940s and the 1960s will be studded with studies on corneal oxygenation, bulb hydration and possible alternatives to plastic, which is still too rigid to produce truly comfortable lenses.
This is how in 1960, Czech medical doctor Ochto Wichterle introduced the first soft hydrogel contact lenses into the market, the prototypes that today’s lenses are based on. This was a starting point; ten years later, Bausch & Lomb will produce the first pair of this type of lens.
From then on, the evolution of contact lenses never stopped, leading to many variations including toric lenses, bifocal lenses, contact lenses cosmetics, daily disposable ones, fortnightly lenses or those for prolonged use.